* Adjective: Describing something as unkind, nasty, or unpleasant.
* Example: "She gave me a mean look."
* Verb: To intend, to signify, or to have a particular value.
* Example: "I mean to do my homework later." or "What does this symbol mean?"
* Noun: The average of a set of numbers.
* Example: "The mean of these numbers is 10."
To determine the part of speech, you need to look at the context of the sentence.