What part of speech is palpitates?

Palpitates can be categorized as a verb.

Parts of speech

1. palpitates is a verb, present, 3rd person singular of palpitate (infinitive).

Verb
palpitate - beat rapidly; "His heart palpitated"
palpitate - cause to throb or beat rapidly; "Her violent feelings palpitated the young woman's heart"
palpitate - shake with fast, tremulous movements; "His nostrils palpitated"