Green’s Dictionary of Slang

gall n.

(orig. US) impudence, arrogance, self-possession.

1865		Leaves from Diary of Celebrated Burglar 55/1: Happen, t’rascal ’ll want t’collar her away from me? If he duz, I’ll bust his gall!
1882		Denver Republican 23 Jan. 4/1: There is only one word which thoroughly expresses the quality of Dr. Anderson’s communication. That word is the strong expression, ‘gall’ [DA].
1896		W.C. Gore Student Sl. in Cohen (1997) 19: gall n. Boldness, impudence, effrontery.
1901		J. Flynt World of Graft 41: Chapman’s got more gall than I have.
1912		Bulletin (Sydney) 24 Oct. 13/1: Her ‘gall’ was a direct incentive to harshness, anyhow.
1921		C.E. Mulford Bar-20 Three 195: You got plenty of gall, comin’ down here an’ throwin’ a gun on me, for that!
1930		J. Lait Put on the Spot 39: They got a grand gall, these here mayors an’ coppers.
1947		Chicago Herald-Amer. 7 Feb. 3/1: The gall of this inveterate crook [...] is as fascinating as any other phase of his revolting character [DA].
1962		Ragen & Finston World’s Toughest Prison 800: gall – High spirits; courage; impudence.
1977		S. Berkoff East in Decadence and Other Plays (1985) 74: What a gall!
1989		M. Amis London Fields 301: An autobiography is, by definition, a success story. But when some pipsqueak takes up his pen as the evenings lengthen – well, full marks for gall!

SE in slang use

In compounds

gall-breaker (n.)

(US) a form of alcoholic drink.

1815

Gent.’s Mag. Apr.n.p.: Do you love your glass, every hour brings with it a fresh bumper. There [i.e. the US] you have the gum-tickler, the phlegm- cutter, the gall-breaker, the antifogmatic.