Hacker (Noun) — Someone who plays golf poorly.
Hacker (Noun) — A programmer who breaks into computer systems in order to steal, change or destroy information as a form of cyber-terrorism.
Hacker (Noun) — A programmer for whom computing is its own reward; may enjoy the challenge of breaking into other computers but does no harm. ex. "true hackers subscribe to a code of ethics and look down upon crackers"
Hacker (Noun) — One who works hard at boring tasks.