A man, generally a younger man.
A term of address for someone, typically a cautioning him or offering him advice.
An inexperienced cowboy.
A tourist.
A man who is very concerned about his dress and appearance; a dandy, a fop.
A term of address, usually for a man, conveying awe, excitement, surprise, etc.
To address someone as dude.
To take a vacation in a dude ranch.
Usually followed by up: to dress up, to wear smart or special clothes.