n.
Pronunciation: ' a-p ə - ˌ t ī t
Function: noun
Etymology: German Apatit, from Greek apat ē deceit
Date: 1803
: any of a group of calcium phosphate minerals occurring in various colors as hexagonal crystals, as granular masses, or in fine-grained masses as the chief constituent of phosphate rock and of bones and teeth especially : calcium phosphate fluoride