throb
     n 1: a deep pulsating type of pain
     2: an instance of rapid strong pulsation (of the heart); "he
        felt a throbbing in his head" [syn: {throbbing}, {pounding}]
     v 1: pulsate or pound with abnormal force; "my head is
          throbbing"; "Her heart was throbbing"
     2: expand and contract rhythmically; beat rhythmically; "The
        baby's heart was pulsating again after the surgeon
        massaged it" [syn: {pulsate}, {pulse}]
     3: tremble convulsively, as from fear or excitement [syn: {shudder},
         {shiver}, {thrill}]
     [also: {throbbing}, {throbbed}]
Source: WordNet® 2.0