molecule

Etymology

From French molécule, from New Latin molecula (“a molecule”), diminutive of Latin moles (“a mass”); see mole + -cule.

noun

1. (chemistry) The smallest particle of a specific element or compound that retains the chemical properties of that element or compound; two or more atoms held together by chemical bonds.
   Hydrogen chloride is a diatomic molecule, consisting of a hydrogen atom and a chlorine atom.
   The critical component of the photosynthetic system is the “water-oxidizing complex”, made up of manganese atoms and a calcium atom. This system splits water molecules and delivers some of their electrons to other molecules that help build up carbohydrates. 2013 September-October, Katie L. Burke, “In the News”, in American Scientist, Sigma Xi, →OCLC, archived from the original on 2013-09-03
2. A tiny amount.