/ Thesaurus / P Synonyms of placental Find synonyms for: Noun1. placental, placental mammal, eutherian, eutherian mammal, mammal, mammalianusage: mammals having a placenta; all mammals except monotremes and marsupialsAdjective1. placental (vs. aplacental), transplacentalusage: pertaining to or having or occurring by means of a placenta; "all mammals except monotremes and marsupials are placental mammals"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language