'nonbloodsucking' is formed in Modern English from the negative prefix 'non-' (from Latin 'non', meaning 'not') combined with the compound 'bloodsucking' (from 'blood' + 'sucking').

'bloodsucking' derives from Old English elements: 'blood' (Old English 'blōd') + the verb 'suck' (Old English 'sūccan'); the negated compound 'nonbloodsucking' is a modern English formation using the prefix 'non-'.

Initially the components simply described 'blood' and the action 'to suck'; assembled as 'bloodsucking' they meant 'feeding on blood', and 'nonbloodsucking' has preserved the straightforward negative meaning 'not feeding on blood'.