'annelida' originates from New Latin (Neo-Latin), specifically the word 'Annelida', where 'annellus' meant 'little ring' and the suffix '-ida' was used to form names of groups (taxa).

'annelida' changed from Latin 'annellus' (a diminutive of 'annulus', meaning 'ring') into Neo-Latin taxonomic usage 'Annelida' in the 19th century and became the standard scientific name for the phylum.

Initially it referred to 'little rings' (the ringed appearance of the body), but over time it evolved into the technical name for the phylum of segmented worms (the current biological meaning).