* Verb: To incline or bend, to rely on or depend on something.
* Adjective: Thin and muscular, not fat.
* Noun: A type of meat with very little fat.
* Adverb: Closely or firmly.
Here are some examples:
* Verb: The tower leaned precariously.
* Adjective: He has a lean physique.
* Noun: I'm having a lean steak for dinner.
* Adverb: Keep your hands lean against the wall.
To determine the correct part of speech, you'll need to look at how the word is used in the sentence.