Is when a chick gives you head and some one calls or interups her resulting in blue balls
Tim had to be a cock blocker so abby didn't finish what she started she busted a half dome
de Kaaaaaaack 25 juin 2009
2 more definitions
The big, rock hard dick of a mountain attracted to the sun.
Gee the mountain in yosemite really couldn't keep that half dome in its pocket.
de Siberiansub 13 juin 2011
To “half-dome” is to engage a person of the opposite sex in rigorous activity for an extended period of time thus rendering their legs inoperable and your own appendages exceptionally sore. Normally, this takes around thirteen hours to complete.
I'd half-dome your mom if I had thirteen hours to waste.
de I-got-Domed 27 juin 2011