What was the nickname of Jeffrey Lebowski, the main character of 'The Big Lebowski'?

After winning Oscars for their 1996 film Fargo, the Coen brothers followed their highest box office earner at the time with the quirky comedy The Big Lebowski. It starred Jeff Bridges as an aging hippie/bowling enthusiast named Jeffrey Lebowski, better known as The Dude, who finds himself entangled in a case of mistaken identity that has "lotta ins, lotta outs, lotta what have yous" with his misfit friends (played by John Goodman and Steve Buscemi) after his rug is peed on. Written with Bridges, Goodman, Buscemi and co-stars John Turturro and Sam Elliott in mind for the roles they play, the Coens say the inspiration for the film came from their love of Raymond Chandler novels, noirs like The Big Sleep, and the handful of colorful people they knew out in Los Angeles. Namely, their Blood Simple producers rep Jeff Dowd, who along with his hippie demeanor has had the Dude nickname for most of his life.

Though its foul-mouthed dialogue left audiences in stitches (to use the parlance of our times), when it opened in March of '98 the film confused even the most diehard Coens fans and became a box office disappointment.