> missionary position; hammer away at; enough to choke a horse; does a wooden horse have a hickory dick?

My my, Dale - you've been lookin' up some quaint expressions!

I think the answer to your query is that the status of most of these kinds of online resources is partial and provisional at best - they are often the fond project of one individual. Even authoritative ones like Quinion, wordorigins [and wwftd ] never claim to be the kind of universal resource you can only get at by massive resources of team scholarship.