Hacker meaning : One who is expert at programming and solving problems with a computer. One who uses a computer to gain unauthorized access to data, or to carry out malicious attacks. A computer security professional. Something that hacks; a tool or device for hacking. A fork-shaped tool used to harvest root vegetables. Someone who hacks. One who is inexperienced or unskilled at a particular activity, especially a sport such as golf or tennis. One who operates a taxicab