One who calls attention to problems people don't want to talk about, often in a fashion that offends others. Connotes a degree of righteous indignation or "uncomfortable truth".
Jim Carrey's exclamation of surprise and shock at the acquisition of new evidence, as seen in "Ace Ventura: Pet Detective". Can also denote happiness, digust, etc.
An Irish jig, syrup, rug. A wig, so called because there is shite all underneath it.
Look at that sorry shiteall on Terry Wogan (Irish radio & tv 'personality'), and Bruce Forsyth's (Brit tv presenter) shiteall looks like a birdsnest, the twat.