chemical

The word “chemical” means relating to chemistry or to substances and their reactions. In plain terms, relating to substances and chemistry, or, as a noun, a specific substance itself.

“Chemical” is pronounced KEHM-ih-kuhl (/ˈkɛm.ɪ.kəl/ in IPA).

Here is “chemical” used in a sentence: “The factory had to follow strict chemical safety rules.”

Depending on how it is used, “chemical” can be an adjective and a noun.

The word “chemical” comes from New Latin. From New Latin chemicus plus the adjective suffix -al, tracing back through alchemy to Arabic al-kīmiyāʔ.

“Chemical” is a fairly common word in modern English, usually learned at around the A2 level.

“Chemical” has 2 distinct senses listed in this dictionary. The most common is: relating to chemistry or to substances and their reactions.

A chemical change creates a new substance through a reaction, like wood burning or iron rusting, and is usually hard to reverse. A physical change alters only form or state — melting ice or tearing paper — while the substance itself stays the same underneath.

A chemical reaction such as baking soda fizzing with vinegar is a classic example. Chemical processes include digestion, photosynthesis, and combustion. The word describes anything relating to substances and how they combine, break apart, or transform — the core subject matter of chemistry.

In everyday speech people contrast "chemical" with "natural," but the distinction is misleading: everything, natural or manufactured, is made of chemicals. Water and oxygen are chemicals too. Scientifically, "chemical" simply means relating to substances and their reactions, not something artificial or harmful.