Surprising cars in remote areas at dusk by standing along the side of the road on your tippy toes, eyeswide, head out, using one hand to make antlers and the other to smoke a cigarette.
Slow down! Is that a moose? Oh wait, it's just some guy Moosing us.
When you get together with a bunch of mooses and do moose stuff. Possible moose activities include speeding, sipping, tripping, dipping, chopping, wubbing, beaning, rolling, and donating to moose conservation groups.
Verb: hitting it from the back whilst making a mocking expression with your hands beside your head in a "nanana boo boo" fassion while they cannot see you.
Dude, I was with this girl and you alreadyknow I was moosing!