'overambitious' originates from the prefix 'over-' meaning 'excessive' and the word 'ambitious' from Latin 'ambitiosus', where 'ambitio' meant 'a going around (to solicit votes)' and '-osus' meant 'full of'.

'ambitiosus' transformed into the Old French word 'ambitieux', and eventually became the modern English word 'ambitious', with 'over-' added to denote excessiveness.

Initially, 'ambitiosus' meant 'full of ambition', but over time, 'overambitious' evolved to mean 'excessively ambitious'.