within

Within is a preposition and an adverb in English that denotes being inside the limits or interior of something, or occurring before a boundary or deadline. It is used to indicate spatial enclosure, temporal proximity, or scope. Examples include: "The notes are stored within the folder," and "Within five minutes, the results will be announced."

Origin and form: The word derives from Old English forms such as wiþinnan or withinne, formed from with and in, and was written as two words or hyphenated in earlier periods. It fused into the modern single form within during Middle English and has retained the sense of being inside a boundary or within a prescribed limit.

Usage notes: In spatial contexts, within often implies interior or interior of a boundary, and is slightly more formal than inside. In temporal contexts, within expresses a limit: "within ten days" means not later than ten days. It also appears in phrases denoting scope, jurisdiction, or capability: "within the law," "within my reach," "within our budget." Common collocations include within reach, within the scope of, within five miles, and within ten minutes.

See also: Related terms include inside and in, and common phrases such as within reach, within the law, and within the scope of.