The word usage is a noun.
The word "usage" can function as a noun.
"When" can function as an adverb, conjunction, or noun in a sentence, depending on its usage.
"Ghetto" can function as a noun, adjective, or verb, depending on its usage.
"Where" can function as both an adverb and a conjunction, depending on its usage in a sentence.
The part of speech of the word "brevet" can vary based on its usage. As a verb, it is typically used as a transitive verb. As a noun, it is commonly treated as a countable noun.
"Altogether" can function as an adverb or an adjective, depending on its usage in a sentence.
It can be a verb or a noun, depending on usage. en.wikipedia.org/wiki/Gerund
"All" can be an adjective, adverb, pronoun or noun depending on the usage.
"Joint" can function as both a noun and an adjective.
In traditional usage, it's most often a noun. In slang usage, it's most often a verb.
Bone is mostly used as a noun. There is a crude usage that would be a verb.
Depending on usage, the English language word "game" can be a noun, an adjective, or a verb.
The word whomever is a pronoun. It is the formal usage of whoever.
The word deploy is a verb. It means to prepare a military unit for usage.
The term for knowing a word's part of speech in order to appropriately use it in a sentence is "word-usage."
The word "species" is a noun. Here is an example of its usage in a sentence: There are over 28,000 species of fish on the planet.
In that usage, it would be an adverb.
The word pledge means the same thing as promise, and as such, it can be either a noun or a verb. For example, I pledge my loyalty to you. That is a verb usage. You have accepted my pledge. That is a noun usage.