black hat

[ blak hat ]
/ ˈblæk ˈhæt /
Informal.

noun

a villain, as in a cowboy movie; bad guy.
Digital Technology. a hacker who violates the security of a system without the knowledge or consent of the owner or developer, as for personal profit or for the gratification of causing damage.

Idioms for black hat

    wear/put on a black hat, to behave villainously.
Compare white hat.

British Dictionary definitions for black hat

black hat

noun

informal
  1. a computer hacker who carries out illegal malicious hacking work
  2. (as modifier)black-hat hackers Compare white hat