The act of entering a vagina whose depth is too shallow to accomodate the penis, thus resulting in said penis hitting the cervix. This, "bottoming out", results in much uncomfortability in the receiving woman.
BottomedOutGirl: It was great up until about 4am. We had dinner, drank a shit load, but when we had sex he bottomed out!
GirlsFriendFromLastNight: Damn girl! Once you saw that dick of his you should have told him about that shallow pussy of yours!