Interesting that the web site differs:

    S: (n) hacker (someone who plays golf poorly)
    S: (n) hacker (a programmer for whom computing is its own reward; may enjoy the challenge of breaking into other computers but does no harm) "true hackers subscribe to a code of ethics and look down upon crackers"
    S: (n) hack, drudge, hacker (one who works hard at boring tasks) 

http://wordnetweb.princeton.edu/perl/webwn?s=hacker