Definition of hemichordate in English:

hemichordate

noun

Zoology
  • A marine invertebrate of the phylum "Hemichordata" ; an acorn worm.

    • ‘We chordates are deuterostomes, as are echinoderms, some marine worms called hemichordates, and the urochordates, or sea squirts.’
    • ‘Size comparisons between living and extinct hemichordate zooids are not conclusive evidence, however, as it is easy to imagine a small, hypothetical, zooid that possessed multiple tentaculated arms.’
    • ‘Molecular phylogenies have suggested that hemichordates are in fact a sister lineage to the echinoderms.’
    • ‘Unfortunately, a change in the genetic code of the mitochondrial genome in both enteropneusts and echinoderms strongly rejects chordate affinities of the hemichordates.’
    • ‘The molecular phylogeny does agree in one respect with the morphological one in that there are close similarities between the larvae of hemichordates (acorn worms and pterobranchs) and some echinoderms.’

adjective

Zoology
  • Relating to or denoting hemichordates.

    • ‘Unfortunately there are no living fenestrate hemichordate species.’
    • ‘There are two classes of hemichordate, the pterobranchs and the enteropneusts, which differ greatly in appearance and lifestyle.’
    • ‘Evidence for the hemichordate affinity of the extinct graptolites has been steadily amassing.’
    • ‘The hemichordate sequences always contained considerable support for both hypotheses.’
    • ‘They lack two others, the notochord and post-anal tail, hence the name hemichordate.’

Pronunciation

hemichordate

/hɛmɪˈkɔːdeɪt/