You can use glimpse as a noun (like when you "catch a glimpse of someone") or as a verb (like when you "glimpse in someone's direction"). Although the word glimpse is usually used to describe the physical act of sneaking a peek at something, you can also use the noun glimpse to indicate a vague idea or suggestion.

Is the definition of glimpse?

a very brief, passing look, sight, or view. a momentary or slight appearance. a vague idea; inkling.

Is one an adjective or adverb?

one (pronoun) one (adjective) one–armed bandit (noun)