in·vag·i·nate Pronunciation Key (n-vj-nt)
tr. & intr.v. in·vag·i·nat·ed, in·vag·i·nat·ing, in·vag·i·nates
To enclose or become enclosed in or as if in a sheath.
To turn or become turned inward.
To infold or become infolded so as to form a hollow space within a previously solid structure, as in the formation of a gastrula from a blastula.
Wow. Try working that one into your everyday conversation.