The Collaborative International Dictionary of English v.0.48:

Phosphorate \Phos"phor*ate\, v. t. [imp. & p. p. Phosphorated;
   p. pr. & vb. n. Phosphorating.] (Chem.)
   To impregnate, or combine, with phosphorus or its compounds;
   as, phosphorated oil.
   [1913 Webster]