'suffix' originates from Latin, specifically the word 'suffixus', where 'sub-' meant 'under' (or 'from below') and 'figere' (root 'fix-') meant 'to fasten'.

'suffix' changed from Medieval/Old French 'suffixe' into Middle English 'suffix' and eventually the modern English 'suffix' (and related forms such as 'suffixing').

Initially it had the sense of 'fastened underneath/attached', but over time it evolved into the linguistic sense 'an element added to the end of a word'.