130 Science Words That Start With D (With Meanings & Examples)

Learning science words that start with D helps you understand key topics in biology, chemistry, physics, and more. These words are used in real-life science and school learning. Whether you’re a student, a teacher, or just curious, this guide will make science easier and more fun.

In this article, you’ll explore 130 science words D learners should know. Each word comes with a simple meaning and an easy example. You’ll also find a science words D table at the end for quick reference. From DNA to diffusion, this is your full science dictionary D words list.

General Science Words Starting With D

These are basic science terms used across all branches of science.

Word	Meaning	Example
Data	Information collected in science	Scientists use data to find answers.
Density	Mass in a certain space	Oil floats because it has low density.
Diffusion	Spread of particles from high to low	Oxygen diffuses into our blood.
Deduction	Using logic to reach a conclusion	She made a deduction from the experiment.
Discovery	Finding something new	The discovery of penicillin saved lives.
Describe	To explain in words	Please describe what you saw in the lab.
Develop	To improve or create something	Scientists develop new vaccines.
Detect	To find or notice something	We can detect bacteria using a microscope.
Design	To make a plan	Design an experiment for plant growth.
Derive	To get from something else	We derive energy from the sun.

Biology Science Words That Start With D

These words are used in life sciences and human biology.

Word	Meaning	Example
DNA	The code that tells cells what to do	Your DNA comes from your parents.
Digestion	Process of breaking food into nutrients	Digestion starts in the mouth.
Diaphragm	Muscle that helps breathing	The diaphragm moves when we breathe.
Dendrite	Part of nerve cell that receives signals	Dendrites carry messages in the brain.
Deamination	Removing part of a protein	Deamination happens in the liver.
Duct	A tube that carries fluid	The tear duct brings tears to your eye.
Detoxify	To remove toxins	The liver detoxifies harmful chemicals.
Dermis	The inner layer of skin	The dermis holds sweat glands.
Diploid	Cells with two sets of chromosomes	Humans have diploid cells.
Dormant	Inactive or asleep stage	Seeds stay dormant until they grow.

Chemistry Words That Start With D

Common terms in labs and chemical studies.

Word	Meaning	Example
Decomposition	Breaking a compound into parts	Water decomposes into hydrogen and oxygen.
Distillation	Separating liquids by boiling and cooling	Distillation is used to make clean water.
Dimer	A molecule made of two similar parts	Oxygen can form a dimer.
Diatomic	Molecule with two atoms	Nitrogen is a diatomic molecule.
Dipole moment	Separation of electric charges in a molecule	Water has a strong dipole moment.
Dilute	To make a solution weaker	Add water to dilute the acid.
Denature	To change shape of a protein	Heat can denature enzymes.
Decant	To pour off liquid without disturbing solids	Decant the liquid from the top.
Detergent	A substance used to clean	Detergents break up oils in water.
Desalination	Removing salt from water	Desalination gives us drinking water from the sea.

Physics Words That Start With D

Used to explain forces, motion, and energy.

Word	Meaning	Example
Displacement	Change in position	The displacement was 5 meters east.
Drag	Air resistance that slows movement	Drag affects airplanes in flight.
Dynamics	Study of forces and motion	Dynamics explains car crashes.
Doppler effect	Change in sound due to motion	A siren sounds different as it passes.
Diamagnetic	Repelled by magnetic fields	Water is a weak diamagnetic substance.
Drive	Power or force that moves something	An electric drive moves the machine.
Drift	Slow movement in one direction	Drift happens in ocean currents.
Diffraction	Bending of waves	Light shows diffraction through a small hole.
Dielectric	An insulator in electronics	Glass is a common dielectric material.
Density meter	Tool to measure density	We use a density meter in labs.

Earth Science Words That Start With D

Focus on land, air, and water science.

Word	Meaning	Example
Delta	Land formed where a river meets a sea	The Nile Delta is good for farming.
Drought	A long dry period	Crops die during a drought.
Deposition	Dropping of materials by wind or water	Rivers leave sand through deposition.
Dust storm	Strong wind carrying dust	Dust storms reduce visibility.
Deforestation	Cutting down trees	Deforestation affects the climate.
Drainage	Movement of water from land	Good drainage stops flooding.
Detritus	Dead organic matter	Detritus is food for small animals in soil.
Destruction	Damage to natural features	Volcanoes cause destruction.
Dew	Moisture on surfaces in morning	Dew forms when air cools at night.
Daylight	Light from the sun during the day	Plants need daylight to grow.

Scientific Tools Starting With D

These are instruments and devices used in labs and science work.

Tool	Use	Example
Densitometer	Measures density	A densitometer checks milk thickness.
Dosimeter	Measures radiation exposure	Workers wear a dosimeter in power plants.
Defibrillator	Restarts the heart	A defibrillator is used during emergencies.
Dropper	Moves small amounts of liquid	A dropper adds drops to a test tube.
Digital scale	Measures mass electronically	We use a digital scale in the lab.
Drying oven	Removes moisture from items	Samples dry faster in a drying oven.
DNA sequencer	Reads DNA codes	DNA sequencers help doctors identify diseases.
Dissecting kit	Used to cut and study animals or organs	A dissecting kit helps in biology class.
Detector	Finds specific substances or particles	Smoke detectors save lives.
Dialysis machine	Filters blood for patients with kidney issues	Dialysis machines are found in hospitals.

Science Words Starting with D for Kids and Beginners

Simple words from science used in primary school.

Word	Meaning	Example
Dinosaur	Prehistoric animal	Dinosaurs lived a long time ago.
Dirt	Soil on the ground	Plants grow in dirt.
Daylight	Light during daytime	We need daylight to see clearly.
Dissolve	Mix into liquid completely	Salt dissolves in water.
Drop	A small round liquid	The drop fell from the leaf.
Duck	Water bird, studied in nature	Ducks swim in lakes and ponds.
Doctor	A person who helps with health	Doctors use science to treat sickness.
Drink	To take liquid in the mouth	Animals drink water every day.
Dust	Tiny dry particles in the air	We breathe in dust during storms.
Dark	Lack of light	Plants don’t grow well in the dark.

Science Words That Start With D – Genetics and Cell Biology

Word	Meaning	Example
Dominant	A strong gene that hides the weaker one	Brown eyes are a dominant trait.
DNA polymerase	Enzyme that copies DNA	DNA polymerase helps in cell division.
Daughter cell	A new cell made by another cell	Each cell makes two daughter cells.
Diploid cell	A cell with two sets of chromosomes	Body cells are diploid.
Disjunction	Separation of chromosomes during cell division	Disjunction happens in meiosis.
Deletion	Missing part of a gene or chromosome	Genetic deletion can cause disease.
Differentiation	Cells becoming special types	Nerve cells come from differentiation.
DNA replication	Copying of DNA before a cell divides	DNA replication happens before mitosis.
DNA fingerprint	Unique code used to identify people	Police use DNA fingerprinting in crimes.
Double helix	Shape of DNA, twisted ladder	DNA’s double helix holds genetic info.

Human Anatomy & Physiology

Word	Meaning	Example
Diaphragm	Muscle that helps with breathing	The diaphragm moves when you inhale.
Digestive tract	Organs that break down food	The digestive tract runs from mouth to anus.
Duodenum	First part of the small intestine	Food moves into the duodenum after leaving the stomach.
Dermis	Inner layer of the skin	The dermis contains sweat glands.
Dendrite	Part of a nerve cell	Dendrites carry messages to the brain.
Deltoid	Shoulder muscle	The deltoid helps raise your arm.
Dorsal	Refers to the back of the body	The spine is on the dorsal side.
Dialysis	Cleans blood when kidneys fail	Dialysis is needed for kidney patients.
Duct	Tube that moves fluid	Tear ducts carry tears to the eyes.
Dislocation	When a bone moves out of place	A shoulder dislocation is very painful.

Science Words That Start With D – Environmental and Earth Studies

Word	Meaning	Example
Drainage	Removing water from land	Good drainage prevents floods.
Deforestation	Cutting down large areas of trees	Deforestation reduces animal homes.
Desertification	Turning land into desert	Overgrazing causes desertification.
Decomposer	Organism that breaks down dead things	Fungi are natural decomposers.
Delta	Land at river’s mouth made by sediment	The Ganges Delta is very fertile.
Dust bowl	Dry area with wind-blown soil	The Dust Bowl damaged farms in the 1930s.
Drain	Pipe that removes water	Water flows through the drain into the sewer.
Dam	Structure to block water	A dam holds water for electricity.
Debris	Leftover broken material	Storms leave behind lots of debris.
Downpour	Heavy rainfall	A downpour flooded the streets.

Science Words That Start With D – Medical and Health Science

Word	Meaning	Example
Diagnosis	Finding out what sickness someone has	The doctor made a fast diagnosis.
Drug	A chemical used for treatment	Antibiotics are a type of drug.
Dose	The correct amount of medicine	The nurse gave a small dose.
Disorder	A medical condition or problem	Eating disorders affect many people.
Diabetic	A person with diabetes	Diabetic patients check sugar levels daily.
Deficiency	Not having enough of something	Iron deficiency causes tiredness.
Disinfect	To kill germs	Disinfect the tools before use.
Durable	Long-lasting, often used for equipment	Durable gloves are used in hospitals.
Delivery	The act of giving birth	She had a smooth delivery.
DNA test	A test to check someone’s DNA	The DNA test confirmed the father.

Astronomy and Space Science

Word	Meaning	Example
Dwarf planet	A small planet-like body in space	Pluto is a dwarf planet.
Dark matter	Invisible mass in space	Dark matter makes up most of the universe.
Distance	Space between two points	The distance between Earth and Mars is large.
Doppler shift	Change in light or sound from motion	Stars show Doppler shifts when they move.
Day	Time it takes a planet to rotate once	Earth’s day is 24 hours.
Declination	Angle above the celestial equator	Astronomers use declination to find stars.
Dust cloud	Group of tiny particles in space	Stars form in dust clouds.
Dome	A curved roof on a telescope building	Telescopes are inside a dome.
Detector	Tool that finds particles or radiation	Space detectors find cosmic rays.
Drive system	Power source for moving spacecraft	The probe uses an electric drive system.

Scientific Processes and Experiments

Word	Meaning	Example
Data analysis	Studying data to find results	The lab used data analysis to check patterns.
Double-blind	A test where nobody knows who gets treatment	Double-blind trials remove bias.
Dependent variable	The factor being measured	Plant height is the dependent variable.
Design	Plan or layout of an experiment	Design your test before you start.
Duration	The length of time something lasts	Measure the duration of each reaction.
Diagram	A simple drawing to explain	Make a diagram of your setup.
Dilution	Making a solution weaker	Use water for dilution.
Degree	A unit of measurement	Water boils at 100 degrees Celsius.
Depth	Distance downward	Measure the depth of the container.
Documentation	Written records of results	Good documentation is key in science.

Conclusion

Now you have a complete list of science words D with simple meanings and examples. These science words for kids D, easy science vocabulary, and scientific words starting with D will help you grow your science language. Use these words when writing, reading, or doing experiments.

This guide is part of a growing science glossary D words list for learners of all ages. Keep exploring more letters and keep learning every day!