Source : Webster's Revised Unabridged Dictionary (1913)

Phosphoryl \Phos"phor*yl\, n. [Phosphorus + -yl.] (Chem.)
   The radical {PO}, regarded as the typical nucleus of certain
   compounds.

Source : WordNet®

Po
     n 1: a radioactive metallic element that is similar to tellurium
          and bismuth; occurs in uranium ores but can be produced
          by bombarding bismuth with neutrons in a nuclear reactor
          [syn: {polonium}, {atomic number 84}]
     2: a noncommissioned officer in the navy with a rank comparable
        to sergeant in the army [syn: {petty officer}, {P.O.}]
     3: a European river; flows into the Adriatic Sea [syn: {Po
        River}]
     4: an independent agency of the federal government responsible
        for mail delivery (and sometimes telecommunications)
        between individuals and businesses in the United States
        [syn: {United States Post Office}, {US Post Office}, {Post
        Office}]