1.girl who is your best friend when she is single and then ditches and forgets who you are as soon as she's with someone
2.a guy who is is big but not muscular ie."thick"
"Ash and Jay are so in love shes been a massball ever since they got together."
"Uh uh i never thought she'd be a massball, yo she a bitch for that:"
"Damn girl ur man is a massball,he too big for you."