Etymology
Advertisement
kerato- 
before vowels, kerat-, scientific word-forming element meaning "horn, horny," also "cornea of the eye" (see cornea), from Greek keras (genitive keratos) "the horn of an animal; horn as a material," from PIE root *ker- (1) "horn; head."
Related entries & more 
Advertisement
hylo- 

word-forming element meaning "wood, forest," also "matter," from Greek hylos "a wood, a forest, woodland; wood, firewood, timber; stuff, material," used by Aristotle for "matter" in the philosophical sense; a word of unknown origin.

Related entries & more 
chondro- 

word-forming element in scientific compounds meaning "cartilage," from Latinized form of Greek khondros "cartilage" (of the breastbone), also "grain, grain of salt, seed, barley-grain," of uncertain origin. This is sometimes said to be from the PIE root meaning "to grind" which is the source of English grind (v.), but there are serious phonological objections and the word might be non-Indo-European [Beekes, "Etymological Dictionary of Greek"]. The body material so called for its gristly nature.

Related entries & more