'enoplan' originates from New Latin (taxonomic usage), ultimately from Greek 'enoplos' meaning 'armed' (from en- 'in' + hoplon 'weapon').

'enoplan' was formed from the New Latin taxonomic name 'Enopla' (the class name in Nemertea), which itself derives from Greek 'enoplos'; the English noun/adjective 'enoplan' developed to denote members of or traits pertaining to Enopla.

Initially the Greek root meant 'armed'; over time the term became specialized in taxonomy to denote nemerteans with an 'armed' (stylet-bearing) proboscis and now refers specifically to members or characteristics of the class Enopla.