A female, typically one with small
breasts. (Often used in a negative context.)
Males may be called chestlets as an
insult, much like calling a
male a "little girl". (Also, may be a more demeaning insult than "manlet".)
"I don't see how anyone can like chestlets, more meat on a woman is better!"
"
Shut up, you chestlet."
"Forget that
slag, she's a chestlet anyway, not worth your
time."