'apotome' originates from Ancient Greek, specifically the word 'ἀποτόμη (apotomē)', where 'apo-' meant 'away, off' and 'tome' (from 'temnein') meant 'a cutting'.

'apotome' passed into Latin (as 'apotoma' or 'apotome') through medieval scholarly usage and was adopted into English from Latin/Medieval Latin mathematical texts describing Euclidean theory.

Initially it meant 'a cutting off' or 'that which is cut off'; over time in mathematical usage it came to mean specifically 'the remainder (a line or magnitude) obtained by cutting one magnitude from another' and thus refers to a classified type of irrational magnitude.