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

The hitch: Major gas basins are growing old, and the country lacks the proper infrastructure to ferry molecules where they are needed.

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Photosynthesis is a sequence of reactions in which electrons pass between multiple pigment molecules.

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Their experiments showed that removing surface proteins known as HLA class 1 molecules allowed NK cells to avoid attack from T cells in the host’s immune system.

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The results also revealed that amyloid beta contributes to cancer in another way - by depleting fumarate, a small molecule made inside mitochondria during energy production.

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That changed in 2023 when Dr. Thu-Thuy Dang and her team in the Irving K. Barber Faculty of Science identified the first plant enzyme capable of twisting a molecule into the distinctive spiro shape.

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Related Words

• fragment 
• particle