Added 9 October 2026
atom
/ˈætəm/ noun
In Latin: atomus Wiktionary
noun Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about atom at Wordnik → Where our words come from →
Origin
From Middle English attome, from Middle French athome, from Latin atomus (“smallest particle”), from Ancient Greek ἄτομος (átomos, “indivisible”), from ἀ- (a-, “not”) + τέμνω (témnō, “to cut”, o-grade in τομ-) + -ος (-os). Atoms are so named because they were historically thought up as to be the smallest unit of matter, and thus indivisible. Doublet of atomus.
From Wiktionary, via Kaikki.org (CC BY-SA)