a rotten apple

a rotten apple

A person whose own words or actions negatively impacts an entire group of people. Taken from the proverb "a rotten apple spoils the bunch." Before you accuse the entire department of wrongdoing, you should try to find the rotten apple that initially caused the problem.
See also: apple, rotten
Farlex Dictionary of Idioms.

rotten apple

a single bad person or thing. There always is a rotten apple to spoil it for the rest of us. Tom sure has turned out to be the rotten apple.
See also: apple, rotten
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

rotten apple

A bad individual among many good ones, especially one that spoils the group. For example, The roommates are having problems with Edith-she's the one rotten apple of the bunch. This expression is a shortening of the proverb a rotten apple spoils the barrel, coming from a 14th-century Latin proverb translated as "The rotten apple injures its neighbors." The allusion in this idiom is to the spread of mold or other diseases from one apple to the rest. In English the first recorded use was in Benjamin Franklin's Poor Richard's Almanack (1736).
See also: apple, rotten
The American Heritage® Dictionary of Idioms by Christine Ammer.

a rotten (or bad) apple

a bad person in a group, typically one whose behaviour is likely to have a corrupting influence on the rest. informal
See also: apple, rotten
Farlex Partner Idioms Dictionary

a bad/rotten ˈapple

one bad person who has a bad effect on others in a group: In response to the allegations of mass corruption within the team, a former player said today, ‘There may be the odd rotten apple in the pack, but the majority are clean and honest.’
See also: apple, bad, rotten
Farlex Partner Idioms Dictionary

rotten apple

n. a single bad person or thing. There always is a rotten apple to spoil it for the rest of us.
See also: apple, rotten
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • a rotten apple spoils the (whole) barrel
  • a rotten apple spoils the (whole) bunch
  • a rotten apple spoils the (whole) bushel
  • bushel
  • a bad apple spoils the (whole) barrel
  • teach a man to fish
  • village
  • it takes a village
  • a man is judged by the company he keeps
  • a man is known by the company he keeps
References in periodicals archive
But it seems to me there's a rotten apple in this barrel.
TIME CALLED ON TIMERS
Here, it's comparing a rotten apple with another rotten apple.
Poe urges public to complain vs bad telco service
London, Jan.19 ( ANI ): Manchester City striker Mario Balotelli is all set to join Italian giants AC Milan in a 24 million pound deal despite club owner Silvio Berlusconi branding him a rotten apple recently.
Balotelli all set for 'dream' AC Milan move despite Berlusconi's 'rotten apple' comment
with help from an accomplice, needed surgery after slipping on a rotten apple while mowing the lawn and getting his foot caught in the mower.
TV quiz cheat loses three toes; weird WORLD
"He's bitter toward me because, I think, there are some third parties, a rotten apple, so to speak, that has manipulated him and turned him into this rotten apple's minion."
Missing drawing further divides political rivals
McDermott added: "Gullit said Alan Shearer was a rotten apple. Well, I'm still a big Newcastle fan and I wish we had 22 rotten apples like him - and I'm sure the rest of the United supporters think the same.
Pathetic
The front page has the heading "Is there a rotten apple in our barrel?"
News in Brief: ROW OVER 'BAD' COPS
The poster asks: "Is there a rotten apple in the barrel?" It comes eight months after the force's Inspector Adam Carruthers was jailed for 12 years for raping two women.
Shop-a-cop poster plea
A rotten apple is just an overly ripe apple, producing enough ethylene to "ripen" the rest of the apples in the barrel.
On Apples and Adages
Prandelli advised Balotelli to listen to Mancini's advice, and added that Berlusconi might have branded the striker as a rotten apple but he has always behaved nicely during national duties.
Italy manager Prandelli tells Balotelli he is no 'super hero'
"He is a rotten apple and could infect every group where he goes, even Milan."
'ROTTEN APPLE' BALOTELLI
London, Jan 9( ANI ): Former Italian prime minister and owner of seven-times European champions AC Milan, Silvio Berlusconi has branded Manchester City striker Mario Balotelli as a rotten apple after it was suggested the forward could make a return to San Siro.
AC Milan boss Berlusconi brands Balotelli 'rotten apple'
The new poster asks: "Is there a rotten apple in the barrel?" and lists the names of individuals and organisations to contact with information.
Cops and rotters call