[ prahy-mawr-dee-uhm ]
/ praɪˈmɔr di əm /

noun, plural pri·mor·di·a [prahy-mawr-dee-uh]. /praɪˈmɔr di ə/. Embryology.

the first recognizable, histologically differentiated stage in the development of an organ.

Origin of primordium

1665–75; <Latin prīmōrdium, in plural: beginnings, elementary stage, equivalent to prīm(us) first (see prime) + ōrd(īrī) to begin + -ium-ium; cf. exordium Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for primordium

British Dictionary definitions for primordium

/ (praɪˈmɔːdɪəm) /

noun plural -dia (-dɪə)

biology an organ or part in the earliest stage of development
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

Medical definitions for primordium

[ prī-môrdē-əm ]

n. pl. pri•mor•di•a (-dē-ə)

An aggregation of cells in the embryo indicating the first trace of an organ or structure.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.