A phrase that can be used in place of any English word when you can't think of what word you're looking for, when you don't have a particular word in mind, or in place of a bad word. Can be used as a noun, verb, adjective, adverb, or full sentence.
Those guys are nothing but a bunch of wamby pambies.
All you have to do is wamby pamby this thing over here.
That wamby pamby dog peed on my foot!
Bill wamby pamby threw a rock at Jim.