Online Medical Classes - Where in Eldest is the answer for"What is the Elvish name for the tailbone of the Spine?" (not medical terms)

Where in Eldest is the answer for"What is the Elvish name for the tailbone of the Spine?" (not medical terms)

i need answers from the actual book "Eldest", not medical terms like coficumex, Coccyx, or Caudal Vertebra.

i haven't read that book.my brother has. i could ask him but i just fought with him.sorry
it's on pg. 599. it should be Edur Carthungave
Good question, cause I'm looking for the same answer (I WONDER WHY). It would be nice to win the sweepstakes!