Green’s Dictionary of Slang

(Ulster/US black) a coarse, stupid peasant.

1880		W.H. Patterson Gloss. of Antrim and Down.
1929		(con. WWI) H. Odum Wings on My Feet 104: You big bloot you, if you stood it I know I can.
1997		Share Slanguage.
1999		Daily Record (Glasgow) 13 July n.p.: Women go into pubs [...] to enjoy a quiet drink with friends. And any halitosis-ridden, hand-wandering blooter who thinks otherwise could find himself stuck up his own optic.