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

Those emissions would have a climate-warming impact roughly equivalent to 27 gas-fired power plants operating year-round, even if the flares burned every molecule of methane released from the wells.

From Salon

Water molecules can also be broken down to obtain hydrogen, which is used in rocket fuel.

From BBC

Howard’s generosity with his actors keeps this ensemble a charged group of clashing molecules.

From Los Angeles Times

Indeed, the production of this molecule is on such a scale that it has major effects on the world’s climate, thanks to its effect on the cloud cover over the oceans.”

From Salon

"We grow the algae and make a lot of it under conditions which make a lot of this particular molecule - the blue," says Mr Griffiths.

From BBC

Related Words

• fragment 
• particle