'autocondensation' originates from the modern combination of Greek 'auto-' meaning 'self' and the English word 'condensation', itself from Latin 'condensare' meaning 'to make dense or thicken'.

'condensation' came into English via Latin 'condensatio' (and Old French influences) and Middle English forms; 'auto-' derives from Greek 'autos' and was later attached as a productive prefix in scientific English to form compounds like 'autocondensation'.

The components originally meant 'self' and 'to thicken/densify'; combined in modern scientific usage to denote specifically a reaction in which identical molecules condense (self-condensation).