'gent's' originates from 'gentleman's', specifically the word 'gentleman', where 'gentle' meant 'noble' and 'man' meant 'male adult'.

'gentleman' transformed into the colloquial term 'gent's' in modern English usage.

Initially, it meant 'a noble or well-mannered man', but over time it evolved into its current meaning of 'men's restroom' or 'men's clothing'.