A big black clirotis, or a triple B.
"Ohhh- weee look at that big black bean, smashin up against her panties! It's makin love juices. Thang phat as hell, finna drench her undies or bust out!"
A women with a large clitoris, usually when erect, but sometimes big even before arousal.
"Ohhh- weee look at that blush thumb, pressin up against her panties. Thang big as hell, finna pop out!"