Green’s Dictionary of Slang

extremely drunk, lit. roaring drunk.

1833		Bell’s Life in London 5 May 2/5: The whole party [...] had come to town to see her away. They got roaring fou.
1838		Belfast News Letter 2 Oct. 1/6: The smith and thee got roaring fou.
1847		Liverpool Mercury 13 Aug. 6/4: Tam, is ‘roaring fou,’ his besotted look [...] giving unquestionable proof of the extent to which he had been indulging in ‘usqueba’.
1858		Fife Herald 21 Jan. 1/7: The young men were to be seen with bottles [...] and sometimes some of them were to be seen going home roaring ‘fou’.
1860		Dayton Dly Empire (OH) 10 Mar. 1/3: Burnett [...] got possession of the bar, and was soon ‘roaring fou’.
1863		Dunfermline Sat. Press 12 Dec. 2/4: Had had seen ‘Laird M’Queen’ ‘roaring fou,’ and bleeding.
1870		Glasgow Herald 26 May 3/2: He gets ‘roaring fou’ with a vengeance.
1877		Leeds Times 16 June 7/1: There is nothing to prevent him from becoming ‘roaring fou’.
1888		Dundee Courier 11 Sept. 4/3: Andrew came home ‘roaring fou’ on Saturday night. His wife was afraid of the noise and left the house.
1892		Dundee Courier 2 Jan. 4/1: They had been celebrating the advent of the New Year together, and both got ‘roaring fou’.
1902		Sheffield Dly Teleg. 10 Oct. 5/4: It is not surprising thast on such liberal [...] fare, the ‘sons of summer’ should get ‘roaring fou’.
1914		Webster City Freeman (IA) 8 Dec. 2/6: Some fellows will get roaring fou, as Burns would say.