1.the pushing of something into itself or partially inside out, like a glove finger pushed into itself, or the condition of something that results from this
2.a hollow organ or body part that has been pushed back inside itself
3.the process of folding a portion of a cell structure inward, e.g. when the cell membrane turns inward during phagocytosis
4.the pushing inward of a layer of cells to produce a hollow ingrowth in something, e.g. when the wall of the blastula forms the gastrula
invaginations