ni·date (n??d?t) intr.v. ni·dat·ed, ni·dat·ing, ni·dates To become implanted in the uterus. Used of a fertilized cell. [nid(us) + -ate.] ni·da?tion n. American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.nidation (na??de???n) n1. (Biology) physiol another name for implantation22. (Zoology) physiol another name for implantation2[from Latin n?dus nest]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ni?da?tion (na??de? ??n) n. implantation of an embryo in the lining of the uterus. [1890?95;