Dude meaning : A man, generally a younger man. (used in the vocative) A term of address for someone, typically a man, particularly when 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. 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. A term of address, usually for a man, conveying awe, excitement, surprise, etc.