the motion of moving ones' hand back and forth whilst keeping the arm straight. This is usually done when a person has come out with a great line usually being an innuendo. the term "Rezzo" is short for "resonate" and comes from the rhyme "arm straight... and resonate!"
Male 1: "dude, I just got laid!"
Male 2: "Good lad" (actions a Rezzo)
Male 1: (also actions a Rezzo)
Male 1: "mate, look at the size of that head on your beer!"
Male 2: "best head ive had in ages!
Male 1 & 2: (action a Rezzo)