molecule

[mol-uh-kyool]

noun

1. Chemistry, Physics.,  the smallest physical unit of an element or compound, consisting of one or more like atoms in an element and two or more different atoms in a compound.

2. Chemistry.,  a quantity of a substance, the weight of which, measured in any chosen unit, is numerically equal to the molecular weight; gram molecule.

3. any very small particle.

molecule

/ ˈmɒlɪˌkjuːl /

noun

1. the simplest unit of a chemical compound that can exist, consisting of two or more atoms held together by chemical bonds

2. a very small particle

molecule

1. A group of two or more atoms linked together by sharing electrons in a chemical bond. Molecules are the fundamental components of chemical compounds and are the smallest part of a compound that can participate in a chemical reaction.

molecule

1. A combination of two or more atoms held together by a force between them. (See covalent bond and ionic bond.)

Other Word Forms

• submolecule noun
• supermolecule noun

Word History and Origins

Origin of molecule¹

First recorded in 1785–95; earlier molecula, from New Latin, from Latin mōlē(s) “mass” ( molar ² ( def. ) ) + -cula -cule ¹

Word History and Origins

Origin of molecule¹

C18: via French from New Latin mōlēcula, diminutive of Latin mōlēs mass, _mole ⁴

Example Sentences

Mitochondria in brown fat can shift from making fuel to generating heat through a molecule called uncoupling protein 1.

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The structures, metal ions connected by carbon-based linkers, have large holes that allow other molecules to flow in and out, almost like rooms in a house.

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It has the advantage of being a small molecule that can be manufactured at tremendous scale.

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Now, Marks will be Lilly’s senior vice president of molecule discovery and head of infectious disease.

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Further research is needed, but the team hopes that continued progress will enable these and similar molecules to advance towards clinical testing in the coming years.

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Related Words

• fragment 
• particle