átomo
/ˈatomo/ · B2 · noun · m
atom
⚛️ á-tomo = a (not) + tomo (cut): the piece that can't be cut any smaller
From Greek átomos, meaning uncuttable. The prefix a- means not, and tomos means a cut or slice. The same root appears in English anatomy and tome. Ancient thinkers used it for the smallest piece of matter.