'zookeeper' originates from the English words 'zoo' and 'keeper', where 'zoo' is a short form of 'zoological garden' and 'keeper' means 'one who keeps or takes care of something'.

'zoo' is derived from the Greek word 'zoion' meaning 'animal', and 'keeper' comes from Old English 'cepan' meaning 'to seize or hold'.

Initially, it meant 'one who keeps animals in a zoological garden', and this meaning has largely remained the same in modern usage.