What is the meaning of Slacker?

One who procrastinates or is lazy.

A person lacking a sense of direction in life; an underachiever.

A member of a certain 1990s subculture associated with Generation X.

A person who seeks to avoid military service.

A user of the Slackware Linux distribution.

to slacken; to loosen

to slackline

Source: wiktionary.org