When a girl with large boobs and overall small body size make it seem as if she could fall forward at any given moment or with the slightest push in the forward direction.
Like when an SUV is top-heavy and could topple over much more easily than a lower roofed car.
When a short girl weighs more than the average because of her large breasts in proportion to her smaller body size. This makes it seems as if her boobs are too big for her body.
"Whoa, did you see that top heavy girl? She could fall over any minute now with boobs that big!"
A girl with abnormally large breasts in proportion to the rest of her body.
She's 5' 8", weighs 140, and 30 of it's in her bra. Damn, that's one top heavy chick!
Something that may fall because of an uneven distribution of weight. In this situation, most of the weight would be distributed at the top of the object, causing it to lose balance and fall.
Dane Cook as a child talking to Kool-Aid man after he breaks into his home: "And they would drink out of him, after debris fell into his open idiot head. Asbestos, lead paint fell into his head. He would pour his fruity blood into glasses, and they would drink his dirty fruity blood out of his open head. No, if that was me, I would be like 'No. No. I don't want a drink from you, I want you to fix this goddamn wall before my dad gets home from work. He's not going to believe a dancing bowl of fruit punch came in here. He's gonna beat me with a toaster, I swear to god bro. This is bulls-No no! Don't touch me! Please. I'll kick you in the legs and you break TOP HEAVY and you will smash.'"
a female with large breasts, usually a D cup or bigger.
Damn, those are nice!
Drunk to the point of being unable to maintain ones balance.
"I barely remember last night, did I drink a lot?"
"Dude, you were top heavy, you could barely stand up."
A person who can't be defined on Urban Dictionary
"Hey Kelcy (not the real bubbles), What's up?"
"Not much, Shmangela, I just got a new definition for myself on Urban Dictionary."
"Oh, well, just like those manly men were saying, I'm way too top heavy to be defined."
"That's soooo awesome!"