Which of the following is NOT noun?

Key idea: Adverbs modify verbs, adjectives, or other adverbs; nouns name people, places, things, or ideas.

• run — can be a noun (for example: "I went for a run") and can also be a verb.

• chair — a concrete noun (for example: "She sat on the chair").

• quickly — an adverb that modifies verbs (for example: "He finished quickly"); it does not name a person, place, thing, or idea.

• peace — an abstract noun referring to a state or idea (for example: "They sought peace").

Conclusion: "quickly" is the only word listed that is not a noun, because it functions as an adverb.