a video of someone videoing a run up of a random slap on someone

it is not raping punching stabbing shooting kicking or a beatdown
IT IS A SLAP TO THE FACE
dont let the media make you believe otherwise(we all know they exaggerate)

when someone gets happy slapd its an unexpected crack and your mate films it on his phone. its usualy moshers as their a walkin target. you dont wana get slapd then dont draw attention to your self simple.

term used to describe one's mood when sleep deprived or tired. Signs of being 'slap happy' include inane rambling, strange remarks, odd random behavior (such as giving oneself a wedgie), uncontrollable laughter at one's own jokes.

when you are extremely tired (like if you stay up 'till 1 or 2 in the morning) and everything makes you laugh

The state of being one may experience after abstaining from sleep for a long period of time. Could be described as being so sleepy that you feel hyper and alert.

to gain massive excitement from slapping people.

adj. (1) this word describes the state of someone who becomes somewhat giddy or abnormal in behavior as a result of being smacked around. It is thus synonymous with punch drunk.
(2) it has also been used to describe a person with a penchant or delight in hitting others, but this is certainly not a noun that refers to the state of happiness produced by the hitting.