A bad guy is a person in a story or film who is considered to be evil or wicked, or who is fighting on the wrong side. You can also refer to the bad guys in a situation in real life.
[informal]
In the end the 'bad guys' are caught and sent to jail.
bad guy in British English
(bæd ɡaɪ)
noun
informal
a person who is regarded as evil, esp a character in a book or film
I got offered quite a few bad guys in American movies.
We aim to put the bad guys in prison and take away their money.
Examples of 'bad guy' in a sentence
bad guy
It's difficult to play opposite the exciting bad guy and not end up in his shadow.
Times, Sunday Times (2007)
He was a retired detective, with a superb record of putting bad guys behind bars.
The Sun (2015)
It's a gripping thriller where the real bad guy turns out to be the uncaring legal system.