* Adjective: This is the most common use. It describes something having the texture of meal, like flour or powder. Example: "The potatoes were mealy and dry."
* Noun: It can refer to the mealworm, a type of beetle larvae. Example: "The chickens were fed mealy."
* Verb: It can be used as a verb meaning "to make or become mealy." Example: "The apples mealyed as they ripened."
So, to determine the part of speech, you need to look at the context of the sentence.