* Noun: When referring to the bird, "dove" is a noun. For example: "The dove landed on the windowsill."
* Verb: When referring to the act of plunging or descending, "dove" is the past tense of the verb "dive". For example: "He dove into the pool."
Let me know if you have a specific sentence in mind, and I can tell you the part of speech for "dove" in that context.