2011_12_09 bough \bou\, noun: A branch of a tree, especially one of the larger or main branches.

bough \bou\, noun:
A branch of a tree, especially one of the larger or main branches.
In the background, behind the pool and beneath the dramatic sidereal display, there is a little tree with a bird perched in its uppermost bough, exactly as there is on the Star card.
 -- Tom Robbins, Half Asleep in Frog Pajamas
He ran up the creeper as easily as though it had been a ladder, walked upright along the broad bough, and brought the pigeon to the ground. He put it limp and warm in Elizabeth's hand.
 -- George Orwell, The Orwell Reader: Fiction, Essays, and Reportage
Bough can be traced back to the Sanskrit word bāhu, meaning “shoulder.”