effaced = thinning of the cervix
engaged = the babies head being in the birth canal. once fully "engaged" your usually ready to give birth.
LOL- I think sweetangel meant effacement was the thinning of the cervix, not uterus.
Engaged is when baby's head is in position for birth (like actually in the birth canal, not just head-down).
I just found this site....
http:/ /www. amazingpregnancy .com/pregnancy- articles/194.html
Is it possible to go in labor if hes not engaged?
Engaged refers to the station your baby is at in your pelvis and effacement refers to the thinning of your uterus. I believe they are totally independent of each other. You can have an engaged baby and no effacement or you can have total effacement and an unengaged baby.