evaginate \E*vag"i*nate\, v.t., -nat*ed, -nat*ing. to turn inside out, or cause to protrude by eversion, as a tubular organ. [1650-60; < LL evaginatus, ptp. of evaginare to unsheath = L e- E- + -vaginare, der. of vagina sheath (see VAGINA)] -e*vag"i*na"tion, n.
Source: Random House Webster's College Dictionary (1997)