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.

A buzz word being used to refer to creators and influencers forming or encouraging unhealthy relationships with their fans. Usually used in the context of young audiences feeling they have a relationship with the influencer due to the huge amount of the influencer’s content they consume. The influencer in question, however, is unaware of the fan’s existence other than the general knowledge of having fans. Common examples include Dream and his stans. These relationships are exacerbated by the influencers confirming they have more than a creator-to-viewer relationship.

The word is circulating due to various YouTube essays about the phenomenon using the word, and therefore people who enjoy complaining about influencers repeating what they heard in the video in any comments section they can find.

due to extreme tiredness one becomes giddy with uncontrollable laughter, also described as naturally high

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.