within (Adverb) — On the inside.
within (Preposition) — Internal to, not outside; located in the bounds of. ex. "within the house"
within (Preposition) — Not more or further than, in the limits of. ex. "she's within sight" ex. "fixed within an hour" ex. "within a whisker of losing"
within (Preposition) — Internal to, involving members of (a group of people). ex. "they argued within themselves"