'immune-stimulating' originates from an English compound of 'immune' and 'stimulating'. 'immune' ultimately derives from Latin 'immunis', where the root meant 'exempt' and 'stimulating' comes from Latin 'stimulare'/'stimulus', where 'stimulus' meant 'goad' or 'incitement'.

'immune' entered English via Latin 'immunis' (and Medieval/Old French forms) and became Middle/Modern English 'immune'; 'stimulate' comes from Latin 'stimulare' (from 'stimulus') and entered English in early modern usage. The compound 'immune-stimulating' is a modern English medical formation combining these elements.

Initially, 'immune' meant 'exempt' and 'stimulate' meant 'to prick or incite'; over time the combined modern expression came to mean 'causing activation or enhancement of the immune system' in biomedical contexts.