What would medieval people call a woman's vagina?

Most likely they would have stepped around it. They would say they wanted to lie with her or take her virtue or some other sort of way to vaguely imply they desired a woman for sex. If they were speaking medically it would have been called something relating to birth such as a birth canal. They would never phrase it as "looking for *insert vagina word here*" in 1206. It wouldn't even be uncommon for young bachelor sailors to not even know how sex works and perhaps the older ones might jovially attempt at explaining it.