'N-acylated' is formed by combining the prefix 'N-' (denoting attachment to a nitrogen atom in chemical nomenclature) with 'acylated', the past participle of 'acylate'. 'Acyl' comes from New Latin 'acylium' (via French 'acyle') referring to a radical or group derived from a carboxylic acid; the suffix '-ate' forms verbs or salts.

The element 'acyl' entered modern chemical vocabulary from French 'acyle' and New Latin 'acylium' in 18–19th century scientific usage. Systematic organic nomenclature later adopted the letter 'N' to specify substitution at nitrogen, producing terms such as 'N-acylate' and its participle 'N-acylated'.

Originally 'acyl' referred to the acid-derived radical itself; over time usage broadened so that 'acylate' and 'acylated' commonly describe the act of introducing an acyl group and the resulting substituted compound (i.e., 'bearing an acyl group').