hacker

(noun) someone who plays golf poorly.

(noun) a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism. Synonyms: cyber-terrorist, cyberpunk.

(noun) a programmer for whom computing is its own reward; may enjoy the challenge of breaking into other computers but does no harm. Examples: "True hackers subscribe to a code of ethics and look down upon crackers."

(noun) one who works hard at boring tasks. Synonyms: hack, drudge.