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

/ mŏl′ĭ-kyo̅o̅l′ /

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

• sub·mole·cule noun
• super·mole·cule 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 magnetic fields can be measured through the Zeeman effect of radiative emissions of atoms and molecules.

From Salon

It works in a new way, blocking the activity of a protein molecule called AKT which drives cancer growth.

From BBC

From there, they sneak past the protective barrier lining the respiratory system and head to the lymph nodes in search of cells that express a particular protein called signaling lymphocytic activation molecule, or SLAM.

From Los Angeles Times

White granulated sugar is composed of microscopic, crystalline sucrose molecules.

From Salon

That would involve a process called "cracking" which breaks down the products into smaller molecules.

From BBC

Related Words

• fragment
• particle