'sound-imitative' originates from modern English as a compound of the noun 'sound' and the adjective 'imitative', where 'sound' meant 'noise' and 'imitative' comes from Latin roots meaning 'to copy or imitate'.

'imitative' derived from Latin 'imitativus' (from 'imitari', to imitate), passed into Middle French/Anglo-Norman and then into English as 'imitative'; 'sound' as a noun for 'noise' has Old English and Germanic origins and combined with 'imitative' in modern English to form the descriptive compound 'sound-imitative'.

Initially, the parts meant 'noise' (for 'sound') and 'tending to imitate' (for 'imitative'), and together they evolved into the compound adjective meaning 'imitating sound' or 'onomatopoeic' in current usage.