thighs tha are the size of dinner hams that jiggle while you run

"THUNDER THIGHS" are a fat girls thighs that are so humoungous, big & fat that they clap together when they walk. This produces a loud noise which goes like "SLAP, SLAP, SLAP" , hence the "thunder" part of the word.

Of a woman, large, broad hips and thighs. One of the most tasteful images possible is a woman of such build in a bikini.

a pair of big ass thighs.

n. huge thighs

Pertaining to a person with very large or fat thighs.

A pejorative term for a person with large thighs, alluding to the sound of thighs hitting against each other.