Meaning
A dishonest, untrustworthy, or thoroughly unpleasant person. The metaphor is of an egg that looks fine on the outside but is rotten inside, so it often carries the extra suggestion that the person's bad character is concealed beneath a respectable surface. Informal; somewhat dated but universally understood. Informal and mildly dated; more judgmental in tone than the playful 'rotten apple'. Regional use: General English.
Origin
Figurative use is documented from 1855 (Etymonline), and the earliest known citation is commonly attributed to Samuel A. Hammett's 1855 novel Captain Priest (Grammar Monster). From the mid-nineteenth century it flourished on both sides of the Atlantic and became a standard item of British public-school and university slang, where a 'bad egg' named a thoroughly nasty character. The literal premise was familiar in a farm economy: a spoiled egg can be hard to spot from the outside until it is cracked open or candled against a light, making it a natural image for hidden bad character. 'Good egg' is a later jocular reversal, not recorded until about 1900.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- bad egg
- bad eggs
- one bad egg
Usage Examples
- The auditor warned the board that one bad egg in procurement had been approving fake vendors for years.
- For every bad egg in the league, there are dozens of coaches who mentor young players for free.
- She seemed friendly enough at first, but her business partners eventually discovered she was a bad egg.