Word library

The quality of being useful, or a public service such as electricity, gas, or water.

To make practical use of something, especially in an effective way.

An imagined place or state in which everything is perfect.

Relating to an imagined perfect society, often unrealistically so.

A period of time spent away from work or study for rest or travel.

The act of giving someone a vaccine to protect them against a disease.

A substance introduced into the body to help it build immunity against a particular disease.

To keep changing your mind or opinion; to be indecisive.

Showing a lack of thought or intelligence; empty of meaning.

A space that contains no matter at all, or very close to none.

An electron in the outermost shell of an atom that can take part in forming chemical bonds.

A number that shows how many bonds an atom of a particular element can typically form with other atoms.

Based on sound reasoning, or legally and officially acceptable.

To confirm that something is true, accurate, or legally acceptable, or to make someone feel their feelings are reasonable.

Official confirmation or proof that something is accurate, legitimate, or meets a required standard.

A low area of land between hills or mountains, often with a river running through it.

Great courage, especially in the face of danger, such as in battle.

Worth a lot of money, or very useful and important.

The importance, worth, or usefulness of something, or the amount of money something is worth.

A road vehicle, larger than a car, used to carry goods or several passengers.

Weak attractions between molecules caused by temporary shifts in their electron distribution, present to some degree between all particles.

The group of people leading the way in a new movement, idea, or trend.

A sweet flavoring made from the pods of a tropical orchid, commonly used in desserts.

To disappear suddenly and completely.

Lacking interest, excitement, or flavor; dull.

A substance in the form of gas, especially one that is usually liquid or solid.

A symbol, usually a letter, that stands for a number that can change or is not yet known.

A measure of how far a set of numbers is spread out from their average, calculated as the square of the standard deviation.

A change or difference in the amount, form, or level of something.

Marked with patches or streaks of different colors.

A number of different types of something, or the quality of not always being the same.

Of several different kinds.

To be different from one another, or to change in size, amount, or type over time.

Relating to the vessels that carry blood or other fluids through the body of an animal or plant.

The network of tubes that carries fluids such as blood or sap through an organism.

A container, often decorative, used to hold cut flowers.

The widening of blood vessels, which increases blood flow and is often triggered by heat, exercise, or certain chemicals in the body.

A person who was granted land by a lord in exchange for loyalty and service, especially in feudal times.

Extremely large in area, size, or amount.

A quantity that has both a size and a direction, or, in biology, an organism that carries and spreads a disease.

A measurement that has both size and direction, such as velocity or force, unlike a quantity that is just a number.

A plant or part of a plant used as food, typically savory rather than sweet.

Plants, or parts of plants, that are grown and eaten as food.

Plants in general, especially the plants that grow naturally in a particular place.

A region defined by the type of plant life that grows there, usually determined by climate.

In a way that shows strong feeling or forceful conviction, often when disagreeing with something.

A machine used for transporting people or goods, such as a car or truck.

A blood vessel that carries blood from the body back toward the heart.