Commonly used to describe someone who is attractive and has an aesthetically pleasing lower back/behind.
Also a lyric in Mic Drop 'I got hella trophies and is hella thick'
Someone who you'd smash any day, they're big bodied with swole legs and thighs. One clap of their asscheeks can cause a sonic boom, with shock waves that can shatter windows and topple buildings
Hitler: damn it, I'm trying to invade Russia, but I'm dummy thicc and the clap of my asscheecks keeps alerting Stalin.