A novelty playing card with an erotic picture of a dude on the back, typically spread eagle with well orchestrated junk presentation. Often given as a gag gift to females but more appropriately hidden in bags/clothing/rooms of dudes for later accidental enjoyment.
Verb form: The act of placing a dude card in someone's gym bag or room. To be "dude carded."
Phil hid a dude card in my gym bag and my mom found it and yelled at me for being gay.