First, let me explain how dictionaries work. The dictionary exists to record the language used by people like me. When I look up a word, as often as not it’s to see if the editors got it right. Occasionally, I’ll look up spelling or etymology.
That said, let me note that willy-nilly means willingly or unwillingly – with or without consent; will ye or nill ye, see? It also has a secondary meaning as an adjective describing vacillation or equivocation; Like shilly-shallying.
If you want to refer to something done in disorganized haste, try harum-scarum. For an existing mess, as a jumble of houshold goods, you could use tohubohu, (Sorry; I’ve been into the thesaurus again) or the more pedestrian topsey-turvey.
Lately I’ve been seeing willy-nilly used incorrectly to mean casually, or impulsively. In these contexts, if you must use a rhyming compound, you might try higgledy-piggledy. It’s not as glaringly incorrect, and it deserves to be used more than it is. For that matter, you can make up your own rhyming pairs. Just don’t just use willy-nilly higgledy-piggledy.
Next week, sleek.