a plan(or anything that is highly intelligent) that can only be thought up by a ninja due to there highintelligence
guy 1 : i came up with a cunning yet highly intelligent plan to obtain more motes of earth guy 2 : BS! tell me?
guy 1 : ok fine
guy 2 : woah that is a ninjenious plan
"Baker, how are you so ninjaous?" "Well it's a natural ability, and it doesn't hurt that I own in UNO anniversary and can climb trees to abandoned buildings wicked fast."