What type of word is sick?

Sick can be an adjective, a verb or a noun.

As an adjective, sick means ill or unhealthy. For example, "I'm feeling a bit sick today."

As a verb, sick means to make someone ill or to vomit. For example, "The smell of the food made me sick."

As a noun, sick means someone who is ill. For example, "There are a lot of sick people in the hospital."