Green’s Dictionary of Slang

goofus n.

(US) an idiot.

1916		A. Baer Rabid Rudolph 4 Dec. [synd. col.] Joe Goofus, accused of being right eend, escaped from the Smithsonian Institute.
1917		Wadsworth Gas Attack 19: Joe Goofus, of the 105th Infantry, was a Wise Guy.
1927		(con. 1917) J.J. Niles Singing Soldiers 5: Why, Oley, you rum-befuddled goovus.
1928		J.P. McEvoy Showgirl 167: Goofus! There’s Jack, Crazy about you.
1930		J. Tully Shadows of Men 246: They’re allus kind to a goofus when he gets old in the pen.
1933		Derby Dly Teleg. 6 Feb. 5/4: ‘He’s not a patch on Henry,’ answered Goofus.
1939		Howsley Argot: Dict. of Und. Sl.
1948		Hully Dly Mail 28 Sept. 8/3: Eddie (Goofus) Brown presents a variety of antics.
1971		L. Bangs in Psychotic Reactions (1988) 59: My mother and her mother and goofus of a 7th grade brother up front.
1987		Atlanta Constitution 10 Nov. A-22/1: The goofus who made a financial and political shambles of UNESCO [...] has been replaced.
2000		C. Cook Robbers (2001) 322: He nodded, listening to Fred hollering at Barney, telling him what a goofus he was.
2003		Simon & Burns ‘Ebb Tide’ Wire ser. 2 ep. 1 [TV script] Later for you, goofus.

In compounds

goofus juice (n.)

(US) alcohol.

1957

‘Weldon Hill’ Onionhead (1958) 226: They had bought all that goofus juice an’ leetle deeleckacies.