Green’s Dictionary of Slang

dud n.2

[? dud n.1 , thence rags and thus one who dresses in them, esp. a dudman, a scarecrow]

1. of a person, a failure, an incompetent, a weakling, a bore.

[UK]Jamieson Etym. Dict. Scot. Lang. (Supplement) n.p.: Applied to a thowless [spiritless] fellow . . . ‘He’s a soft dud’ .
[UK]A. Binstead Pitcher in Paradise 195: It’s all dam fine for your young military duds to come a-bettin’ on the nod an’ playin’ up the ‘pure boy’.
[UK]A.G. Empey Over the Top 118: You blankety-blank dud, I have been trying to raise you for fifteen minutes. What’s the matter, are you asleep?
[UK]V. Palmer Passage 134: ‘I’m a real dud as a housekeeper,’ she confessed.
[UK]D. Footman Pig and Pepper (1990) 110: I had had a presentiment that my immediate neighbours would be duds from the point of view of company, and duds they were.
[US]H. Miller Sexus (1969) 120: He wasn’t an artist, to be sure, but then he wasn’t a dud either.
[US]N. Spinrad Bug Jack Barron 17: A [...] dud like that Johnson.
[US]J. Langone Life at the Bottom 24: Someone in front of me mutters, ‘Pencil, you dud’.
[UK]T. Blacker Fixx 45: This little detour down Dud Avenue.
[UK]Indep. Rev. 29 June 4: Stud or dud? The top 10 things women look for in men.
[UK]M. Amis Experience 246: Members of both sexes were ranked as one of the following: a dud, a possible, a smasher.

2. anything that lit. or fig. ‘does not work’.

[UK]Marvel XV:388 Apr. 1: I hope this will not prove a dud!
[UK]‘Doss Chiderdoss’ ‘The Sweet Old Names’ Sporting Times 4 Apr. 1/3: I have told fairy stories to Mary, / And to Jane I’ve oft whispered a wheeze; / But they’re chestnuts to Maisie, back numbers to Daisy, / And the veriest ‘duds’ to Louise.
[Aus]Aussie (France) 4 Apr. 4/1: [of shells] He gave in – till a couple of duds came over, and then he tried to get out again, chirping: ‘Lubbly li’le duds! Lemme catch ’em!’.
[UK]‘Sapper’ Black Gang 348: Just this one final coup, old girl [...] If it’s a dud, we’ll dissolve ourselves.
[US]L.E. Lawes Twenty Thousand Years in Sing Sing 221: I told a story about the necessity for mutual understanding. It was a dud, went flat – no laughs.
[UK]S. Jackson Indiscreet Guide to Soho 52: He publishes four a month out of thousands of duds.
[Aus]D. Niland Big Smoke 42: He might have had no heart, no stamina, no nothing. He might have turned out a dud.
[US]Current Sl. III–IV (Cumulation Issue).
[US]B. Malamud Tenants (1972) 18: If I don’t write this novel exactly as I should – if, God forbid, I were to force or fake it, then it’s a dud.
[Aus]N. Keesing Lily on the Dustbin 78: I have heard it said of a jockey who rode a couple of ‘duds’.
[UK]D. Farson Never a Normal Man 311: She had cut the coffee-stall scene and another dud to save time.
[UK]Indep. on Sun. Culture 27 Feb. 3: A perfect dud.

3. of a thing or event, a failure, a disappointment, a ‘flop’.

[UK]‘Doss Chiderdoss’ ‘Scenic’ Sporting Times 11 Feb. 1/4: ‘Though the piece may be a dud, the leading lady scored all right,’ / Said a gentleman who’d had three lines to spout.
[UK]‘Sapper’ Human Touch 124: I’m thinking we’ve struck a dud in this house.
[US]C.G. Booth ‘Stag Party’ in Penzler Pulp Fiction (2006) 113: If i pull a dud i lose my badge.
[US]J. Evans Halo in Blood (1988) 213: They sat there and blinked at me. My bombshell was a dud.
[US]Source Aug. 38: That Poli Sci album was a dud.

In compounds

dudhead (n.) [-head sfx (1)]

(US) an idiot; also as adj.

[US]J. Horwitz Candlelight 171: ‘I need some truth, some truth,’ he was saying to a magnificent dudhead blonde [HDAS].
‘zzzzz00’ posting ‘The K -- saga continues’ 28 Jan. at [Internet] Apparently, as any dudhead would have guessed the screenplay has lots of flaws and just like any Balaji Telefilms serial, it doesn’t give importance to logic!!