noun. We're probably not talking about a bootyliciously firm heinie here--more like a goddamn clenchbutted state of affairs.
Related terms: suck-buttitude, kick-buttitude, needle-buttitude.
Real citation: "The only whites exempt from tight-buttitude are two kids (kids are hip by default in such stories, and are by nature more wise than their benighted parents) and a curious mutant creature played by Eugene Levy -- a middle-class laywer so up on the very latest urban lingo that each of his utterances seems like a tape recorded reading of a hip-hop lexicon."
("ugh...," March 18, 2003, http://www.amazon.com/gp/cdp/member-reviews/A2QN6WUEPY82P2/002-6742189-6220830)
Made-up citation: "Christ's faithful freely assume this manner of life in institutes of consecrated life which are canonically established by the competent ecclesiastical authority. By vows or by other sacred bonds, in accordance with the laws of their own institutes, they profess the evangelical counsels of chastity, poverty and tight-buttitude. Because of the charity to which these counsels lead, they are linked in a special way to the Church and its intestinal tract."