Definition of "invaginate"

(biology) sheathed

(biology) Having one portion of a hollow organ drawn back within another portion.

(medicine, surgery) To fold up or enclose into a sheath-like or pouch-like structure, either naturally or as part of a surgical procedure.  examples

(medicine) To turn or fold inwardly.  examples

(medicine) To fold inward to create a hollow space where none had existed, as with a gastrula forming from a blastula.  examples