Easton's Bible Dictionary (1897)
Heb. peres = to “break” or “crush”, the lammer-geier, or bearded vulture, the largest of the whole vulture tribe. It was an unclean bird (Lev. 11:13; Deut. 14:12). It is not a gregarious bird, and is found but rarely in Palestine. “When the other vultures have picked the flesh off any animal, he comes in at the end of the feast, and swallows the bones, or breaks them, and swallows the pieces if he cannot otherwise extract the marrow.
The bones he cracks [hence the appropriateness of the name ossifrage, i.e., “bone-breaker”] by letting them fall on a rock from a great height. He does not, however, confine himself to these delicacies, but whenever he has an opportunity will devour lambs, kids, or hares. These he generally obtains by pushing them over cliffs, when he has watched his opportunity; and he has been known to attack men while climbing rocks, and dash them against
the bottom. But tortoises and serpents are his ordinary food...No doubt it was a lammer-geier that mistook the bald head of the poet AEschylus for a stone, and dropped on it the tortoise which killed him” (Tristram’s Nat. Hist.).
Smith's Bible Dictionary (1863)
(the bone-breaker). The Hebrew word occurs, as the name of an unclean bird, in (Leviticus 11:13) and Deuteronomy 14:12 It is probably the lammergeyer, or bearded vulture as it is sometimes called, one of the largest of the birds of prey. It well deserves its name ossifrage, bone breaker, for “not only does he push kids and lambs and even men off the rocks, but he takes the bones of animals that other birds of prey have denuded of the flesh high
up into the air and lets them fall upon a stone in order to crack them and render them more digestible even for his enormous powers of deglutition. Marrow-bones are the dainties he loves. This is probably the bird that dropped a tortoise on the bald head of poor old AEschylus.”—N. H. Simpson.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
OS'SIFRAGE (Heb. the breaker). The original word well suits the remarkable habits of the lammergeier, or bearded vulture, known also among the Alps, and one of the most formidable birds of its tribe. It is mentioned with the ospray, as above. The propriety of the name "ossi-frage" - i.e., "bone-breaker" - is seen from the following description: "Marrow- bones are the dainties he (the lammergeyer) loves the best; and when the other vultures have
picked the flesh off any animal, he comes in at the end of the feast and swallows the bones, or breaks them and swallows Ossifrage or Lammergeier (Gypaetus barbatus). the pieces if he cannot get the marrow out otherwise. The bones he cracks by taking them to a great height and letting them fall upon a stone. This is probably the bird that dropped a tortoise on the bald head of poor old AEschylus. Not, however, that he restricts himself, or the
huge black infant that he and his mate are bringing up in one of the many holes with which the limestone precipice abounds, to marrow, turtle, bones, and similar delicacies; neither lamb, hare, nor kid comes amiss to him, though, his power of claw and beak being feeble for so large a bird, he cannot tear his meat like other eagles. To make amends for this, his powers of deglutition are enormous." - N. H. Simpson.