A name for a female who has extremely large breasts, or in some cases can be joked around using a guy as the argument.
Guy1: That group of chicks from IONA are a bunch of big tit bettys (BTB's). I wouldn't mind titty fucking one of them.
Guy2: Yer, no shit.

Guy1: I saw this porn the other night, this chick had massive tits.
Guy2: Yet another big tit betty (BTB) making it big in the porn industry.
Guy1: Huh? Shut up.

Guy1: During PE that guy Crockster took off his shirt and damn, he is one massive BTB.
Guy2: Gross dude.
by Mummas September 4, 2005
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