a pushover, like a noob.
Bobert: Wow, that kid that plays runescape is such a ninny. I stole all his money, ate his girlfriend, and fed him to a boar and he didn't even think twice about it!
Sam: Hey man, wanna play some b ball?
Cheechee: Well, I uh, I kinda wanna play some more runescape.
Sam: You fucking ninny.