'neuroprotectant' is a modern English formation combining the prefix 'neuro-' (from Greek 'neûron' meaning 'nerve') with 'protectant' (from Latin/French roots related to 'protect').

'neuro-' comes from Greek 'neûron' and entered English via New Latin/modern scientific coinage; 'protectant' is built on English 'protect' (from Old French 'protegier'/'protéger', from Latin 'protegere'). These elements were combined in modern scientific English to form 'neuroprotectant'.

Initially formed to mean literally 'an agent that protects nerves'; over time it has been used specifically in medical and research contexts to denote drugs or compounds that reduce neuronal injury or degeneration.