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Compound

KOM-pownd (noun), kuhm-POWND (verb) /ˈkɒmpaʊnd/ (noun), /kəmˈpaʊnd/ (verb)

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generaltechnical

(noun) A substance formed when two or more chemical elements are chemically bonded together in a fixed ratio; (verb) To make (something bad) worse; to combine to form a whole.

In chemistry, a compound is distinct from a mixture because its components are chemically bonded and lose their individual properties. The verb form often implies making something more complex or worse.

The story behind the word. The word 'compound' comes from the Latin 'componere,' meaning 'to put together.' It's formed from 'com-' (meaning 'together') and 'ponere' (meaning 'to place'). This origin clearly reflects its core meaning of combining things, whether it's chemical elements forming a new substance or different problems adding up to a larger one.

Word relationships

mixture: A mixture's components are not chemically bonded; a compound's are.
substance: More general; a compound is a specific type of pure substance.
aggravate: (verb) To make worse, but 'compound' often implies adding to the problem.

element: An element is a pure substance consisting of only one type of atom; a compound is made of two or more elements.
simplify: (verb) To make less complex.

Commonly confused with

Mixture: A mixture's components are physically combined but retain their identities; a compound's components are chemically bonded and form a new substance.

Word family

compounded (adjective): made up of several parts; made worse
compounding (noun): the act of combining or making worse

Collocations

chemical compound
organic compound
inorganic compound
compound interest
compound fracture

Idioms & expressions

to compound a problem

Example sentences

"H2O is the chemical formula for the compound water, showing two hydrogen atoms for every one oxygen atom." Water is a chemical compound formed from hydrogen and oxygen.
"Many pharmaceutical drugs are complex organic compounds designed to interact with biological systems." The scientist worked to synthesize a new organic compound with medicinal properties.
"The sudden job loss served to compound his already stressful situation." His financial difficulties were compounded by unexpected medical bills.

Memory hook

Think of 'COM-bine' and 'COM-pound' – you're putting things together, often to form a new whole or to make a situation more complex. Put together, new substance.

When not to use

Do not use 'compound' (noun) for a simple mixture where components retain their individual properties (e.g., salt and pepper mixed). Do not use 'compound' (verb) to mean simply 'add to' without the implication of worsening or combining into a single entity.

Fun facts

The number of known chemical compounds is vast, with millions of organic compounds alone, far outnumbering inorganic compounds.
The concept of compounds and elements was crucial to the development of modern chemistry, distinguishing it from alchemy.