Meaning of the word "bad apple" in English

What does "bad apple" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

bad apple

US /bæd ˈæp.əl/
UK /bæd ˈæp.əl/
"bad apple" picture

Idiom

a person who creates problems or causes trouble for others in a group

Example:
One bad apple can spoil the whole barrel.
The manager had to fire the bad apple in the team to maintain morale.