When a girl's butt looks good in tight jeans, but it busts out of those jeans when she takes them off in the same way as a can of biscuits when you open the can.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

A small, but lifted butt.

Cute and in-shape

Alexa Bliss' ass

Means a “bitch.”