birth canal

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The passageway through which the fetus is expelled during parturition, leading from the uterus through the cervix and the vagina.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy The combined vagina and cervix, when the cervix dilates during birth to form a continuous tube with the vagina.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a passage in the uterus and vagina through which a fetus passes during vaginal birth