WordNet sense 1 (the porous calcified substance from which bones are made):

osseous tissue

WordNet sense 2 (rigid connective tissue that makes up the skeleton of vertebrates):

os

WordNet sense 3 (a shade of white the color of bleached bones):

ivory, off-white, pearl

WordNet sense 4 (study intensively, as before an exam):

cram, drum, swot, get up, bone up, grind away, mug up, swot up

WordNet sense 5 (remove the bones from):

debone

WordNet sense 6 (having bones especially many or prominent bones):

bony, boney