envaginacion 30
RAE says invagination, action and effect of slip that it means folded inward edges of somewhat tubular, whether organic or not, unite this divided tubular reality by introducing partially one end on the other, as it is done in the bowel surgery, either or introduce something different in this tubular reality, as the sword into the sheath. (Latin Etymology: in-: in, inside and vagina vaginae: sheath, sheath. )