[Upsadaisy!] or [Upsee-daisy!] or [Upsy-daisy!] {adv. phr.} - A popular exclamation […]

[upset the applecart] or [upset one's applecart] {v. phr.}, {informal} To […]

[upside down] {adv. phr.} Overturned so that the bottom is up […]

[upstairs] See: [NOBODY HOME UPSTAIRS].

[ur] "You're" or "your"

[urban homesteading] {n.}, {informal} Renovation and occupation through cooperative ownership by […]

[URT] "Urban Terror"; A mod for Quake III

[URYYFM] "You are too wise (two Ys) for me"

[use] See: [NO USE], [PUT TO USE].

[use every trick in the book] {v. phr.}, {informal} To avail […]