Rather than give a REAL definiton, I've decided to go thesaurus on your asses:

Bosoms, Breasts, Bloomings, Crease Creatures, Deltoid Drawers, Fatsacks, Baby Fodder, Bust, Mamories (or Mammilla), tits, teats, udders, Monkey Lumps, Scapula Scones, Milkmeat, Globes, Tits, Infant Eateries, the Latter Lickable Ladyparts, Tatas, Dodongoes, Pearls, Thoraxes, Clavicle Clumps, Objects-of-my-desire, Suckling Stops, Endowment, Lactators, East and West Cleavage, Cones, Torpedoes, Eye Magnets, Chest Bulges, Flesh Convexities, the Weasels of the Chest, Where boys fear to tread, Porcelain Hills (the former adjective exchangeable with "ebony" or "golden"), Whack-Material, What Good dreams are Made of, the Ass-of-the-chest, Mounds, Grapefruit (or Oranges, Melons, and, in rare (and creepy) cases, grapes. The elderly are prone to "prunes"), Effeminite Masses, Knockers, Kitty Substitutes, Not-so-grassy Knolls, Jigglies, Hillocks, Gibbosities, Conjoined Humpbacks, Stacks, Bouncers, or Breasticles.

what you have to look at when a girl is talking to you

Hooters - boobs and also a restaurant chain.

Main eating establishment for men whose girlfriends have small breasts.

Owls

melons, juggs, balloons, implants, honkers, XL breasts

a woman's breasts(jocular)