'acylamino' originates from the combination of 'acyl' and 'amino', where 'acyl' refers to a functional group derived from an acid by removal of a hydroxyl group, and 'amino' refers to a functional group containing a nitrogen atom bonded to hydrogen atoms.

'acylamino' was formed by combining the terms 'acyl' and 'amino' to describe a specific chemical group in organic chemistry.

Initially, it meant 'a compound containing an acyl and amino group', and this meaning has remained consistent in modern usage.