A yammo can have a few differentdefinitions, depending on context. In general, it is used to refer to a person who is or is acting like an idiot, fool, moron, dimwit, simpleton, tool, lunk head, asshole, jerk, etc.
freedom-loving creature;not to be caged or kept as possesion, good humored,loves to tease and flirt with opposite sex, straight forward in conversation, intellecutal but superficial, sometimes irresponsible and careless, always sexy and mysterious, must aproach with caution. Very tempermental!!!!