Moroobs are basically manboobs on a girl. She only has a huge rack because she is fat, or morbidly obese. Morbid+boobs= Moroobs.
Novis: Ugh! Look at that fat bitch in the drive thru.
Amelio: Her fucking tities are on the steering wheel.
Novis: Silly Amelio, those aren't tities, those are moroobs.
Amelio: My bad blood, and look, the only reason her moroobs stay lifted is cuz they are resting on her fat ass belly.