/in vaj'euh nay"sheuhn/ , n.
1. the act or process of invaginating.
2. Embryol. the inward movement of a portion of the wall of a blastula in the formation of a gastrula.
3. Pathol. intussusception (def. 3).
4. a form or shape resulting from an infolded tissue.
[ 1650-60; INVAGINATE + -ION ]