What part of speech is killer?

"Killer" can be a few different parts of speech depending on its context:

* Noun: A person who kills, especially a murderer.

* Adjective: Extremely good or impressive.

* Verb: To kill. (This is less common and typically used in a slang or informal way.)

Examples:

* Noun: "The police are searching for the killer."

* Adjective: "She has a killer smile."

* Verb: "He killed the game with his amazing performance."