'girlish' originates from the Old English word 'gyrlisc', where 'gyrl' meant 'girl' and '-isc' was a suffix meaning 'pertaining to'.

'gyrlisc' transformed into the Middle English word 'girlish', and eventually became the modern English word 'girlish'.

Initially, it meant 'pertaining to a girl', and this meaning has largely remained the same in modern usage.