'arteriolar' originates from New Latin/modern English formation, specifically from the noun 'arteriole' plus the adjectival suffix '-ar', where 'arteriole' meant 'small artery' (a diminutive of 'artery').

'arteriole' came into English via Modern Latin 'arteriola', a diminutive of Latin 'arteria' (from Greek 'artería'), and the adjective 'arteriolar' developed by adding the suffix '-ar' to form 'relating to arterioles'.

Initially the root referred to a 'small artery', and over time the adjective form evolved to mean 'relating to or characteristic of arterioles' rather than naming the vessel itself.