Function can be a noun and a verb.
Noun: What something is used for.
Verb: To have a function.
The word "snappy" can function as an adjective.
The word "steal" can function as a verb.
The word "gentleman" can function as a noun.
The word "abide" can function as a verb.
The word "bulletin" can function as a noun.
The word "chair" can function as a noun.
The word "nuclear" can function as an adjective.
The word "congregation" can function as a noun.
The word "cultivate" can function as a verb.
The word "conceive" can function as a verb.
The word "quick" can function as an adjective.
The word "beach" can function as a noun.