from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The implantation of the early embryo in the uterus

from The Century Dictionary and Cyclopedia

  • n. The development of the endometrial epithelium in the intermenstrual periods.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. (embryology) the organic process whereby a fertilized egg becomes implanted in the lining of the uterus of placental mammals


Sorry, no etymologies found.


  • For some it dates from the first instant; for others it could not at least precede nidation implantation in the uterus.

    Do Embryos Have Souls?

  • Pregnancies are medically recognized conceptions, often defined as beginning at implantation or nidation roughly a week after fertilization.

    The Population of the United States

  • Adverse effects on nidation in rats, embryo viability in mice, and metabolism in vitro of rat testis and human spermatozoa have been attributed to Lithium, as have teratogenicity in submammalian species and cleft palate in mice.


  • If the question of when life begins depends on objective science, where has the scientific community confirmed that it overwhelmingly and definitively favors fertilization over implantation [or nidation]?

    U.S. News


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