1. Not doing very much of anything.

2. Not doing what you are meant to be doing.
Stop slacking off Steve
by PowerGlide May 09, 2015
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Slacking off at this time, when there's so much to do? (to slack off)
by anything more November 21, 2011
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The act of one giving themselves an over-the-pants handie, whereas they are either unable or too lazy to pull their pants down and masturbate correctly.
"This morning at work John was totally caught slacking-off under his desk."

"I always slack-off at dinner on the first date."
by StonyBear November 10, 2011
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To masturbate, jack off, stroke your penis, fap, beat your wiener, play with yourself,
My penis was a boner so I slacked off.
slack off.
by Minecraft1238 February 07, 2019
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