'seizure-preventing' originates from Modern English, specifically the words 'seizure' and 'preventing', where 'seizure' came to English via Old French 'seisiure' / 'seisir' meaning 'an act of taking' or 'taking possession' and 'preventing' is from Latin 'praevenire' (via French/Latin-derived English 'prevent') where 'prae-' meant 'before' and 'venire' meant 'to come'.

'seizure' changed from Old French 'seisiure' (from verb 'seisir') and became the English noun 'seizure' (later also used for 'sudden attack'). 'Prevent' is from Latin 'praevenire' -> Old French 'prevenir' -> Middle English 'preven(n)ten/ prevent', and the present participle 'preventing' formed in Modern English; the compound 'seizure-preventing' is a modern English formation combining them.

Initially, 'seizure' primarily meant 'an act of taking or taking possession', but over time it gained the additional sense of a 'sudden attack' (medical). 'Prevent' originally meant 'to come before' and evolved to mean 'to stop or hinder beforehand'; combined, the compound now means 'intended to stop seizures'.