[ trof-uh-blast, troh-fuh- ]

  1. the layer of extraembryonic ectoderm that chiefly nourishes the embryo or develops into fetal membranes with nutritive functions.

Origin of trophoblast

First recorded in 1885–90; tropho- + -blast

Other words from trophoblast

  • troph·o·blas·tic, adjective

Words Nearby trophoblast Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

British Dictionary definitions for trophoblast


/ (ˈtrɒfəˌblæst) /

  1. the outer layer of cells of the embryo of placental mammals, which is attached to the uterus wall and absorbs nourishment from the uterine fluids

Origin of trophoblast

C19: from tropho- + -blast

Derived forms of trophoblast

  • trophoblastic, adjective

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

Scientific definitions for trophoblast


[ trōfə-blăst′ ]

  1. The outermost layer of cells of the blastocyst, which attaches the fertilized ovum to the uterine wall and serves as a nutritive pathway for the embryo. The trophoblast eventually differentiates into such tissues as the amnion, the placenta, and the umbilical cord.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.