Word library

So important or sacred that it must never be broken, changed, or disrespected.

Not able to be seen.

A request for someone to come to an event or to do something.

To ask someone to come to an event or to do something.

A document sent to a customer listing goods or services provided and the amount owed.

To include something as a necessary part, or to require someone's participation.

Taking part in something, or, describing a situation, complicated.

A process in which ions in a solution are swapped for different ions held on a solid material, often used to soften or purify water.

A chemical bond formed when one atom transfers an electron to another, creating oppositely charged ions that attract each other.

Easily made angry.

Showing shifting rainbow-like colors that change depending on the angle of light.

A hard, strong metal, or an electrical appliance with a heated flat surface used to smooth wrinkles out of clothes.

The period in human history following the Bronze Age, marked by the widespread use of iron for tools and weapons.

A situation or use of language in which the actual result or meaning is the opposite of what was expected.

The process of exposing something to radiation, often to kill bacteria or treat a medical condition.

A number that cannot be written as a simple fraction of two whole numbers, and whose decimal form never repeats or ends.

Impossible to deny or prove wrong.

Unable to decide or commit firmly to a course of action.

A lack of proper respect for people or things that are usually treated seriously.

Impossible to change, undo, or cancel.

The supply of water to land or crops using channels or pipes.

A man-made channel built to carry water from a source to farmland or other areas that need it.

The form of "be" used with he, she, it, or a singular noun.

A piece of land completely surrounded by water.

A line on a weather map connecting points that have the same atmospheric pressure.

Describing atoms, ions or molecules that have the same number of electrons and the same arrangement of them.

To separate someone or something from others.

The state of being separate and apart from other people or things.

A national policy of avoiding involvement in the political and military affairs of other countries.

A line on a map connecting points that share the same value, such as height or temperature.

Compounds that share the same molecular formula but differ in how their atoms are arranged.

Occurring at a constant temperature.

A solution that has the same solute concentration as the fluid inside a cell, so there's no net movement of water in or out.

One of two or more forms of a chemical element that have the same number of protons but a different number of neutrons.

An important topic or problem that people discuss or need to deal with, or a single edition of a magazine.

A narrow strip of land that connects two larger areas of land and has water on both sides.

Used to talk about a thing, animal, or idea that was already mentioned.

An uncomfortable feeling on the skin that makes you want to scratch.

A single thing, especially one on a list or among a group of things.

Traveling from place to place, especially for work, rather than staying in one location.

A planned route or detailed schedule for a journey.

Shows that something belongs to an animal, thing, or idea already mentioned.

Used to refer back to a thing, animal, or idea that is the subject of the sentence.

A hard, cream-colored material that forms the tusks of elephants and some other animals, or the pale color of this material.

A climbing plant with dark green leaves that spreads over walls and trees.

A short coat, usually worn over other clothing for warmth.

A large, powerful wild cat with a spotted coat, found in Central and South America.

A sweet, thick spread made by cooking fruit with sugar.