Definition of nidation in US English:



  • another term for implantation
    • ‘Reabsorption of these minute embryos due to lack of nidation will lead the dog owner to believe that conception did not occur when in fact it did.’
    • ‘It is essential for the nidation of the conceptus and is thought to inhibit myometrial contractility, thereby ensuring that the uterus is kept in a quiescent state throughout pregnancy.’
    • ‘It was noted that progesterone alone, in contrast with the rat which requires oestrogen for nidation, can maintain blastocysts through nidation in the ovariectomized hamster.’
    • ‘The tissue sample should be aspired either with a Novak cannula or with a plastic Cornier's Pipelle around the time when nidation normally takes place, which means between day 20 to 22 of the cycle.’
    • ‘If Price intended this, did he not, by intending that a nidation be prevented, either then or later, necessarily intend to induce abortion?’


Late 19th century: from Latin nidus ‘nest’ + -ation.