1. Pertaining to the distinct curvature, shape and appearance of the female posterior, amplified by the wearing of leggings or tights. (More commonly referred to women who actually have attractive rear ends.)
2. The butt that is created by the wear of tights or leggings on females. Attractiveness of the region is dependent upon the style, use and condition of clothing worn.
Leroy: Damn! You see her ass in those leggings?
Jake: Yeah, she got that *tight-butt.
Kim: Should I wear tights or stockings with this outfit?
Laura: Tights, duh! You've got the booty for tight-butt!