gram

The word 'gram' entered English in the late 18th century from French 'gramme', a term adopted during the development of the metric system. Its ultimate source is the Late Latin 'gramma', denoting a small weight, which was borrowed from Greek. The Greek 'gramma' originally meant 'something written, a letter', deriving from the verb 'graphein' (to write, scratch, or draw), as the smallest unit of writing. The semantic shift from a written character to a tiny weight is attributed to the use of the same Greek term for a small unit of mass in the Hellenistic period, likely via the weight of a coin or a small scale weight, which then became standardized in the metric system as one thousandth of the base unit, the kilogram.

The word is a simplex loanword from French. It originates from the Late Latin 'gramma', meaning a small weight, which itself came from the Greek 'gramma', meaning a small weight or something written, from 'graphein', to write. In this context, its role is as a complete, unanalyzable unit in modern English denoting a unit of mass.