extension (Noun) — A mutually agreed delay in the date set for the completion of a job or payment of a debt. ex. "they applied for an extension of the loan"
extension (Noun) — Act of expanding in scope; making more widely available. ex. "extension of the program to all in need"
extension (Noun) — The spreading of something (a belief or practice) into new regions.
extension (Noun) — An educational opportunity provided by colleges and universities to people who are not enrolled as regular students.
extension (Noun) — Act of stretching or straightening out a flexed limb.
extension (Noun) — A string of characters beginning with a period and followed by one or more letters; the optional second part of a PC computer filename. ex. "most applications provide extensions for the files they create" ex. "most BASIC files use the filename extension .BAS"
extension (Noun) — The most direct or specific meaning of a word or expression; the class of objects that an expression refers to. ex. "the extension of 'satellite of Mars' is the set containing only Demos and Phobos"
extension (Noun) — The ability to raise the working leg high in the air. ex. "the dancer was praised for her uncanny extension" ex. "good extension comes from a combination of training and native ability"
extension (Noun) — Amount, degree or range to which something extends. ex. "the wire has an extension of 50 feet"
extension (Noun) — An additional telephone set that is connected to the same telephone line.
extension (Noun) — An addition to the length of something.
extension (Noun) — An addition that extends a main building.