Function: noun
Date: 1869
: any of various phosphates of calcium: as a : the phosphate CaH 4 P 2 O 8 used as a fertilizer and in baking powder b : the phosphate CaHPO 4 used in pharmaceutical preparations and animal feeds c : the phosphate Ca 3 P 2 O 8 used as a fertilizer d : the naturally occurring phosphate Ca 5 (F,Cl,OH,1/2CO 3 )(PO 4 ) 3 that contains other elements or radicals and is the chief constituent of phosphate rock, bones, and teeth