bad egg

plural bad eggs

1. UKUSidiomaticSomeone whose behaviour is reprehensible or irresponsible; a rogue.

   My son had a drug problem and hired a bad egg as a chief accountant […]

   1990, John Updike, Rabbit at Rest

   3 more examples

   "Dat's right!" piped up the newsboy who had brought the policeman. "I see him do de trick jest a minit ago!" "This is a plot against me!" fumed the swindler. "Dat feller is a bad egg!" went on the newsboy. "His name is Bill Butts. He's a slick one, he is. Hits de country jays strong, he does!"

   1906, Horatio Alger, Joe the Hotel Boy

   I've been a fairly bad egg, Byrne, for a great many years; but, by George! I'm not entirely rotten yet.

   1914 October – 1916 July, Edgar Rice Burroughs, chapter X, in The Mucker, Chicago, Ill.: A[lexander] C[aldwell] McClurg & Co., published 31 October 1921, →OCLC

   "And the fifth immortal we know tried to kill you." "He is a bad egg. We stick to good eggs."

   2017 May 26, Dan Shive, El Goonish Shive (webcomic), Comic for Friday, May 26, 2017

2. literalAn egg that has gone bad; a rotten egg.