Green’s Dictionary of Slang

egg n.2

1. a person, usu. qualified by adj.; esp. as good egg n. (2); old egg etc.

[[UK]Shakespeare Macbeth IV ii: son.: Thou liest, thou shag-hair’d villain. mur.: What! you egg. Young fry of treachery!].
implied in bad egg under bad adj.
[US]T.A. Dorgan in Zwilling TAD Lex. (1993) 28: Making a sick call upon a hard boiled egg who overfed at an outing where the eats were free.
[US]R. Lardner Big Town 233: Some egg in the gallery hollered ‘You said a mouthful, kid!’.
[US]S. Lewis Elmer Gantry 391: Makes me indignant, those spiritual cold-storage eggs not supporting you!
[US](con. 1910s) J.T. Farrell Young Lonigan in Studs Lonigan (1936) 19: He must look like some queer egg.
[US]R. Chandler ‘Blackmailers Don’t Shoot’ in Red Wind (1946) 78: Who don’t, you poor egg?
[Can]M. de la Roche Whiteoak Heritage (1949) 122: At the moment I think you’re rather a queer egg.
[US]S. Lewis Kingsblood Royal (2001) 254: He’s [...] a very smart egg.
[US](con. 1944) N. Mailer Naked and Dead 334: What an odd egg Hearn is.
[US]M. Spillane One Lonely Night 77: The manager told me he was a stupid egg.
[US]J. Blake letter 8 Sept. in Joint (1972) 222: This ticktock, dingdong, jargon-hung, gimmick-headed little fat rotten egg.
[US] ‘Sl. of Watts’ in Current Sl. III:2 40: Righteous egg, n. A good guy.
[US]T. Berger Sneaky People (1980) 202: He turned out to be a real rotten egg.
[US]Graziano & Corsel Somebody Down Here Likes Me, Too 97: I have never seen so many nice eggs in my life.
[UK]S. Gee Never in My Lifetime in Best Radio Plays (1984) 64: Gently. You’ve got your brain in there, you daft egg.
[US]G. Jen Typical American (1998) 172: A rotten egg, my brother called me, to my face.
[Aus]R.G. Barratt ‘Ambos Have to Cop It Sweet’ in What Do You Reckon (1997) [ebook] [S]ome egg with a scratch on his finger.

2. (US) an important person.

[US]Ade ‘The Fable of the Red-Letter Night’ in True Bills 31: The Pilkinses were all the Eggs in Smartweed. They owned a big General Store [...] they sent to Chicago for their Clothes and ate Ice-Cream in the Winter-Time.

3. (also double-yolker) a fool or obnoxious person.

[US]S. Smith ‘The Gumps’ [comic strip] Get a plumber quick, you egg.
[US]J. Callahan Man’s Grim Justice 142: Then I suddenly decided she was an egg and that I didn’t love her at all.
[US](con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 338: I wonder what museum those eggs came from.
[US]R. Prather ‘Double Take’ in Best of Manhunt (2019) [ebook] ‘When did you see this egg in my office?’.
[Aus]J. Alard He who Shoots Last 119: There’s rotten eggs in all walks of life.
[NZ]G. Newbold Big Huey 91: ‘Fuck off, you egg!’ they shouted. [Ibid.] 156: ‘I told you he was a double-yolker, didn’t I?’ ‘Yeah, he’s a fucking mug.’.
[Aus]T. Winton Human Torpedo 122: No, don’t be an egg.
[NZ]A. Duff One Night Out Stealing 13: These kinda people are eggs, as they call it in the vernacular here.
[Aus]P. Doyle (con. late 1950s) Amaze Your Friends (2019) 236: ‘All those people listed there, every one of them is a blue-ribbon egg.’ ‘Egg?’ ‘An easy mark’.
[US]Eble Campus Sl. Sept. 3: egg – socially awkward person; a loser; someone who doesn’t belong to the cool crowd.
[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 61/1: double yolker n. an idiot; a stupid, incompetent person.
[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 65/1: egg n. 2 (also <b>eggroll</b>) an idiot, a stupid person.

4. (US Und.) the victim of a confidence trick.

[US]D. Maurer Big Con 27: The joint wanted to know how much your egg would blow.

In phrases

old egg (n.)

a man or woman, esp. as a term of affectionate address.

[Aus]Aussie (France) XIII Apr. 15/2: I’ve just had a long chat with the dear old Colonel – precious old egg!
[UK]Wodehouse Inimitable Jeeves 14: The old egg had the air of one who has something up his sleeve.
[US]Monteleone Criminal Sl. (rev. edn).
[UK]Wodehouse Jeeves and the Feudal Spirit 178: Very handsome of you, old egg.
[Aus]‘David Forrest’ Hollow Woodheap 61: His rouseabout is a rough, old egg from Malaya.
[US]B. Jackson Get Your Ass in the Water (1974) 70: Me, myself, I’m a wise old egg, / I can lie, steal, or beg.