hack·er / ˈhakər/ • n. 1. inf. an enthusiastic and skillful computer programmer or user. ∎  a person who uses computers to gain unauthorized access to data.2. a person or thing that hacks or cuts roughly.3. a person who plays amateur sports without talent or skill: for the weekend hacker, a set of basic golf clubs should suffice.

hacker
1. A person who attempts to breach the security of a computer system by access from a remote point, especially by guessing or otherwise obtaining a password. The motive may be merely personal satisfaction, for example by endeavoring to access a system in another country, but it may occasionally have a sinister intent.

2. Originally, a person who had an instinctive knowledge enabling him or her to develop software apparently by trial and error.

hacker In computing, a person who obtains unauthorized entry to a computer database. A hacker, who usually gains access through the public telephone system using a modem, may read or even alter the information in the database.