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 form, change shape, deform - assume a different shape or form

bulk - stick out or up; "The parcel bulked in the sack"

jut, jut out, protrude, stick out, project - extend out or project in space; "His sharp nose jutted out"; "A single rock sticks out from the cliff"

protuberate - form a rounded prominence; "The starved child's belly protuberated"

change form, change shape, deform - assume a different shape or form

swell - cause to become swollen; "The water swells the wood"