invagination noun.
[ɪn,vadʒɪ'neɪʃ(ǝ)n] M17.[mod. Latin invaginatio(n-), formed as IN-2 + VAGINA: see -ATION.]Orig., the action of sheathing something;
esp. intussusception. Now usu., the folding in of a surface or membrane to form a hollow cavity or pouch; the cavity so formed.
[TahlilGaran] English Dictionary ▲