Green’s Dictionary of Slang

1. (orig. sporting) to make a blunder, to make a mess, to trip up.

1857		G. Lawrence Guy Livingstone 49: I don’t see why you should have muffed that shot.
1861		T. Hughes Tom Brown at Oxford (1880) 148: They muffed it in the Gut, eh?
1887		World (N.Y.) 26 July 3/1: On Daly’s muffing Ward’s fourth strike ‘Buck’ crossed the plate.
1890		‘F. Anstey’ Voces Populi 63: Everyone muffs it at starting.
1902		Ade Girl Proposition 28: After about two Moves she would hand him a Liner which he would Muff.
1905		N. Gale ‘The Old Professional’ in More Cricket Songs 35: God knows I’ve muffed some easy chances / Of doing good, like a silly lout.
1914		R. Lardner You Know Me Al (1984) 71: The eighth started with Shanks muffing a fly ball off Bodie.
1916		A. Brazil Luckiest Girl in School 136: ‘If any of you muff the ball or do anything stupid. I’ll never forgive you!’.
1922		T. Thursday ‘Ten Dollars – No Sense’ in Top-Notch 15 Dec. 🌐 He leaped for it like a greyhound after a bone, fell on his bean, rolled over in the gutter, and grinned. He muffed it by a block.
1930		R.E. Howard ‘Fist and Fang’ Fight Stories May 🌐 You had your chance, and you sure muffed it! I licked you then, and I can lick you now.
1944		J. Archibald ‘Jail, Jail, the Gang’s All Here’ in 10 Detectives Aces Apr. 🌐 The only good crime story in a year and you muff it.
1949		P. Pringle Boy’s Book of Cricket 68: He [...] muffed it because of the sun in his eyes.
1953		J. Thompson Savage Night (1991) 143: They’d muffed their chance to catch me in the act.
1960		C. Cooper Jr Scene (1996) 105: Davis had told him [...] to make a buy from Bertha Travis, and he had muffed it!
1970		A. Sillitoe Start in Life (1979) 235: I was being trusted with the big job, and if I muffed it William Hay would get his face bashed in.
1985		N. Pileggi Wiseguy (2001) 161: Our players had to muff enough shots to make sure that they won by less than the bookie’s ten points.
1999		E. George ‘I, Richard’ Evidence Exposed (1999) 113: Malcolm had worried a bit that Betsy might muff her role in the ensuing drama.
2000		Indep. Rev. 25 Feb. 14: Not knowing the jazz progressions / He muffed the middle eight.
2011		Eve. Standard 13 Apr. 32/1: I totally muffed it.

2. to fail an examination.

1884

J. Sturgis in Longman’s Mag. III 617: Freddy and Tommy and Dicky have all muffed for the army. It’s really dreadful! [F&H].

3. of a bill, to suffer a default.

1918

T. Thursday ‘Nearly Over’ in Top-Notch 15 Apr. 🌐 He’ll get paid just as soon as some of those dyspeptic editors slip me some coin. It won’t be the first bill he’s muffed.