Definition of annelid in US English:



  • A segmented worm of the phylum Annelida, such as an earthworm or leech.

    • ‘After examining the opening of these traces, it is tempting to assign their origin to the behavior of vermiform borers such as annelids, sipunculids, or phoronids.’
    • ‘The annelids include earthworms, polychaete worms, and leeches.’
    • ‘Most biologists are familiar with only a few of the approximately 40 extant animal phyla such as annelids, arthropods, molluscs, echinoderms and chordates.’
    • ‘Arthropods, chordates and annelids are the three segmented phyla in the animal kingdom.’
    • ‘The position and composition of these cells suggests that they are homologous to the gliointerstitial cell system of molluscs, sipunculans, annelids echiurans.’
    • ‘Silurian ramphoprionid polychaete annelids, represented by their jaws, are described from extensive collections from Gotland, Sweden.’


  • Relating to or denoting annelids.

    • ‘These differences in expression domains indicate changes in the regulation of these genes somewhere in the annelid lineage.’
    • ‘When present, the annelid peritoneum either rests directly on the muscle cells or is separated from them by a layer of extracellular matrix.’
    • ‘If reptiles could develop into birds then annelid worms could develop into insects.’
    • ‘It is clear that two different hydrophobic motifs are conserved in annelid species.’
    • ‘These genomes have remarkably similar gene orders to previously published annelid genomes, suggesting that gene order is conserved across annelids.’