slacker: someone with a low motivation level and an aversion to work

While slacker has an early nineties ring for most of us, it is actually a much older word. Richard Linklater's 1991 movie Slacker may have helped popularize the word as a term for an aimless, unambitious sort of young person. However, it has meant a lazy shirker since the nineteenth century. During the first world war, it could refer to someone who was unwilling to undertake military duties.

The adjective slack, which gives us slacker, is even older. The Oxford English Dictionary traces it back to a common Germanic root with a general meaning of looseness or carelessness. It is related to Middle Dutch slac, Old High German slach, Icelandic slakur, Norwegian and Swedish slak, and Danish slag. It's also connected with Latin laxus, meaning loose or languid, and Greek lagos 'with drooping ears', the word for a hare. Related English words include lax, languid, and relax. Ultimately slacker goes all the way back to the Indo-European root *sl¯eg-, to be languid. It seems that shirking work is an ancient human trait. Instead of avoiding 9-to-5 jobs, maybe Indo-European slackers resisted herding sheep in favor of hanging around with their friends, drinking mead.