To ride one's motorcycle either alone or in a group. Can be determined and high speed, or just out for a Sunday run.
1: "Good hoon?" "Yeah, lamped it down the A13 at 130mph!"
2: "We're off for a hoon at the weekend - probably going to take in some Oxfordshire twisties, maybestop for lunch if we find a nice pub".
"that dog is hooning that man's leg" or "that girl has very nice hoons" or "i hooned all over my new pants" but not "hoon you motherhooner!" or any such expletive context.