'immunoenhancing' originates from the combining form 'immuno-' (from Latin 'immunis') and the verb 'enhance' (from Old French 'enhauncer'/'enhauncer', ultimately related to Latin 'altus' meaning 'high'), where 'immunis' meant 'exempt, free' and the roots of 'enhance' carried the sense 'to raise' or 'to make higher'.

'immuno-' was coined in modern medical English as a combining form from Latin 'immunis' (via Middle English 'immune'), and 'enhance' came into English from Old French 'enhauncer'; these were combined in modern English into the compound adjective 'immunoenhancing' to describe agents or properties that raise immune function.

Initially the elements referred separately to 'exemption/free' ('immunis') and 'raising' ('enhance'); over time the compound came to mean specifically 'raising or boosting immune function' in biomedical usage.