Someone who is especially lazy, indolent, or given to procrastination. I don't know how a slack master like him manages to get straight A's.That slack master Janet has been pulling our whole project down. I think she's done about 10 minutes of genuine work!
slackmaster
n. someone who slacks off a lot; someone who doesn’t work hard enough or at all. He never does his share. Nothing but a slackmaster!