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

Alexander Tarakhovsky added that it was striking to see immune-related molecules, long recognized for their roles in B and T lymphocytes, also influencing microglia.

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Scientists have long debated whether water in these confined regions simply behaves as a passive bystander or affects how molecules interact.

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One possibility involves light-sensitive molecules that respond to magnetic conditions and could allow the animal to see magnetic patterns.

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This interaction temporarily stabilizes the molecules, allowing reactions to proceed.

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They found that paclitaxel, a commonly used chemotherapy drug, prompts immune cells to produce large amounts of reactive oxygen species, which are molecules that place cells under stress.

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Related Words

• fragment 
• particle