frontal eminence - either prominence of the frontal bone above each orbit

occipital protuberance - prominence on the outer surface of the occipital bone

belly - a part that bulges deeply; "the belly of a sail"

caput - a headlike protuberance on an organ or structure; "the caput humeri is the head of the humerus which fits into a cavity in the scapula"

mogul - a bump on a ski slope

nub, nubble - a small lump or protuberance

snag - a sharp protuberance

wart - any small rounded protuberance (as on certain plants or animals)

projection - any solid convex shape that juts out from something

change posture - undergo a change in bodily posture

neck, make out - kiss, embrace, or fondle with sexual passion; "The couple were necking in the back seat of the car"

have, take - have sex with; archaic use; "He had taken this woman when she was most vulnerable"

fornicate - have sex without being married

copulate, mate, couple, pair - make love; "Birds mate in the Spring"