Source : Webster's Revised Unabridged Dictionary (1913)

Palpitate \Pal"pi*tate\, v. i. [imp. & p. p. {Palpitated}; p.
   pr. & vb. n. {Palpitating}.] [L. palpitare, palpitatum, v.
   intens. fr. pappare. See {Palpable}.]
   To beat rapidly and more strongly than usual; to throb; to
   bound with emotion or exertion; to pulsate violently; to
   flutter; -- said specifically of the heart when its action is
   abnormal, as from excitement.

Source : WordNet®

palpitate
     v 1: cause to throb or beat rapidly; "Her violent feelings
          palpitated the young woman's heart"
     2: shake with fast, tremulous movements; "His nostrils
        palpitated" [syn: {quiver}, {quake}]
     3: beat rapidly; "His heart palpitated" [syn: {flutter}]