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endochondral ossification

n.
  1. The formation of bone in which a cartilage template is gradually replaced by a bone matrix, as in the formation of long bones or in osteoarthritic ossification of synovial cartilage.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.