Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
egg tooth[′eg ‚tüth]
a hard sharp horny nodule in the embryos of certain reptiles (turtles, crocodiles, tuatara) and birds that develops temporarily on the upper jaw or on the tip of the upper part of the bill, respectively. The egg tooth serves to break through the shell. Immediately after the egg hatches, the egg tooth falls off. In some lizards and snakes the egg tooth is the anterior tooth of the premaxillary bone.