Hands that are covered in a generous layer of semen, usually after having given multiple hand jobs. Jizz hands make completing everyday tasks a real hassle.
*Phone rings*
Mom: "Sweetheart, can you answer my phone. I have jizz hands at the moment. You're father packs one hell of a load!"
Son: "Ok."
*Son answers phone with a fresh pair of jizz hands of his own after spanking his meat, covering the phone in a crucible of hot semen*