'unconvincible' originates from the prefix 'un-' meaning 'not' and the word 'convincible' from Latin 'convincere', where 'con-' meant 'together' and 'vincere' meant 'to conquer'.

'convincere' transformed into the Old French word 'convaincre', and eventually became the modern English word 'convince', with 'unconvincible' forming as a negation.

Initially, it meant 'not able to be conquered or persuaded', and this meaning has largely remained the same in modern usage.