The word 'zookeeper' is a modern English compound, formed in the 19th century following the establishment of public zoological gardens. Its first element, 'zoo', is a clipped form of 'zoological garden', with 'zoological' deriving from the Greek 'zōion', meaning 'living being' or 'animal'. The second element, 'keeper', comes from the Old English verb 'cēpan', meaning 'to hold' or 'to care for', with the agent suffix '-er' denoting a person who performs the action. Thus, a zookeeper is literally 'one who keeps or cares for animals in a zoological garden', a transparent and logical description of the occupation.

Structure: zoo (animal enclosure) + keeper (one who keeps or guards) - zoo: Origin: Shortened from 'zoological garden'. Ultimate origin: Greek 'zōion' (animal). Role: Base word, specifying the location/context. - keeper: Origin: Old English 'cēpan' (to seize, hold). Role: Agent noun suffix '-er' added to the verb 'keep', meaning 'one who keeps or guards'.