What rule applies most closely to the word exhaust?

The Word "exhaust" can function as both a verb and a noun, with its verb form meaning to use up resources or energy, and the noun form referring to waste gases from an engine. In terms of grammatical rules, it follows standard conjugation patterns for verbs in English. As a regular verb, its past tense is formed by adding "-ed," resulting in "exhausted." Additionally, when used as a noun, it typically refers to the byproducts of combustion in engines.