“+ noun
or hy·droxy·apatite (|)hī|dräksē+
Etymology: hydroxylapatite from German hydroxylapatit, from hydroxyl (from English) + apatit apatite; hydroxyapatite from hydroxy- + apatite
: apatite containing hydroxyl: as
a. : apatite in which hydroxyl predominates over fluorine, chlorine, and carbonate
b. : calcium phosphate hydroxide Ca 5 (OH)(PO 4 ) 3 — calcium phosphate 1b(2)