• synonyms


[lans-lit, lahns-]
  1. any of several small, lancet-shaped burrowing marine animals of the subphylum Cephalochordata, having a notochord and bearing structural similarities to both vertebrates and invertebrates.
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Origin of lancelet

First recorded in 1565–75; lance2 + -let
Also called amphioxus.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for lancelet

Historical Examples

  • By "launces" the writer meant what we should now call the lancelet.

    The Cornwall Coast

    Arthur L. Salmon

  • The lowest of the Vertebrata, the Lancelet (see p. 140), has a larva of this kind.

  • The Lancelet also differs from the true vertebrates, in that it has no limbs.

  • There is a huge gap between the Lancelet and the true vertebrates.

  • The liver in the lancelet is a long diverticulum of the intestine.

British Dictionary definitions for lancelet


  1. any of several marine animals of the genus Branchiostoma (formerly Amphioxus), esp B. lanceolatus, that are closely related to the vertebrates: subphylum Cephalochordata (cephalochordates)Also called: amphioxus
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Word Origin

C19: referring to the slender shape
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

lancelet in Science


  1. Any of various small, transparent, fishlike marine organisms of the subphylum Cephalochordata that are related to vertebrates but have a notochord instead of a true backbone. Unlike other primitive chordates, lancelets have a body divided into serially repeated muscular segments. Also called amphioxus
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.