'Aotus' originates from New (Modern) Latin, specifically from Greek elements where 'a-' meant 'without' and 'ōtos/ōt-' (from 'ous, otos') meant 'ear'.

'Aotus' was formed in scientific Latin as a genus name from ancient Greek word elements ('a-' + 'ōt-'), and the term entered zoological nomenclature as the name of the genus for these night monkeys.

Initially, the components meant 'without ear' (referring to the inconspicuous or less prominent external ear), but over time the compound 'Aotus' came to be used specifically as the taxonomic name for this group of New World monkeys.