'enoplonemertean' originates from modern taxonomic formation combining New Latin elements: 'Enopla' + 'Nemertea', where the prefix/root 'enoplo-' comes from Greek 'enoplós' meaning 'armed' and 'Nemertea' derives from Greek 'Nemertes' (a proper name used in forming the phylum name).

'enoplonemertean' was formed in modern zoological/taxonomic usage by joining 'Enopla' (a taxon name applied to nemerteans with a stylet-bearing proboscis) and the phylum name 'Nemertea', resulting in the English taxonomic noun 'enoplonemertean'.

Initially, the roots signified 'armed' (enoplós) and the phylum name Nemertea; over time the compound came to denote specifically those nemertean worms classified in Enopla (i.e., 'armed nemerteans'), a meaning retained in current scientific usage.