slacker Syllabification: (slack·er)Pronunciation: /ˈslakər/Translate slacker | into German | into Italian Definition of slacker noun informal a person who avoids work or effort. a person who evades military service. a young person (especially in the 1990s) of a subculture characterized by apathy and aimlessness. slacker in other Oxford dictionaries Definition of slacker in the British & World English dictionary