'simiiformes' originates from New Latin, specifically from the combination of Latin 'simia' and the Greek-derived suffix '-iformes', where 'simia' meant 'ape' and '-iformes' meant 'having the form of'.

'simiiformes' developed as a taxonomic formation combining Latin 'simia' and the suffix '-iformes' used in Modern Latin/biological nomenclature; it was adopted in modern taxonomy to name the infraorder 'Simiiformes' denoting ape-like primates.

Initially it literally indicated 'ape-like forms', but over time it became the formal taxonomic name for the infraorder comprising higher primates (monkeys and apes, including humans).