Black Hat
Noun · Hacker Culture
Definitions
A hacker who exploits vulnerabilities for personal gain, malice, or criminal purposes — in contrast to white-hat (ethical) and grey-hat hackers. Also the name of a prominent annual cybersecurity conference (Black Hat USA/Europe/Asia) where researchers present cutting-edge vulnerability disclosures and offensive security research.
In plain English: A hacker who breaks into systems illegally for profit or harm, or the famous security conference named after them.
Example: "The conference is called Black Hat but ironically it's full of defenders trying to learn how attackers think."