A estimation, often influenced by inebriation or equal mental hinderance, of a woman's observed bra size from a male perspective. Often used/found in places like college bars, night clubs, gentleman's clubs, etc.
"My breastimations could have been inaccurate, it was dark."
by Nate Metheny April 17, 2006
Two guys are in a bar and one says, "Hey dude! Check out her twins... What do you think?". The second guy says, " Well, in my breastimation they are heavenly!".
by AdGuy January 17, 2015