Like the more notable, strap on, the dick on a belt allows a person without a penis to engage in pleasuring their partner(s) with a large, hard, cylindrical object.

The dick on a belt can refer to a homemade strap on as well, which is constructed of your everyday dildo/vibrator, a belt & perhaps some duct tape.
Jenny came over last night and fucked me with her dick on a belt.
by Garrand57 April 20, 2011
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Belt that has a dildo as the belt buckle. (Homemade Strap-On or Pivot man in a box)
Carl: Matt I like your dick belt, whose shape is it?

Matt: It's my best friend Kyle.
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