When a male is performming a sexual act involving a woman's breasts as a form of masturbation while straddling her (also known as titty fucking), the male throws up on her breasts while at the same time farting (with anal leakage occurring, but not necessary) on her abdomen. Ergo: Thunder (fart), Mountain (titty fuck), chowder (throwing up).
Upon a very drunken evening, my room mate perfomed a Thunder Mountain Chowder on an excessively irritating, yet equally unlucky female necessitating her taking a shower and him washing his bed linens several times.
by Tea-bagger October 27, 2004
Lo que pasa cuando no te sale el duro. Esperas hasta que la chica salga para España para contarles a tus amigos que vomitaste en su pecho despues de echarle un pedo.
Mr. Stewder performed a thunder mountain chowder on that nice girl from Spain; he'd had too much to drink after eating some bad chile and couldn't get it up.
by d133dr3 November 09, 2004