- (Scotland, obsolete) Used by servants in medieval Scotland to warn passers-by of waste about to be thrown from a window into the street below. The term was still in use as late the 1930s and 1940s, when many people had no indoor toilets.
- (Scotland, historical) A cry of "gardyloo".
- (figuratively) Caution, warning.
- An act of discarding waste or some other substance from a height. Also attributive and figurative.