@Gabz @cheri I've seen it once or twice in older literature. Comes from the French ‘laver' to wash. I'd say you'd be unlikely to find it anywhere today unless reading one of those terrible terrible ebooks pumped out by people who think you can't ever use the same word twice or use normal and common words.
@Gabz I bet it’s the root of lavatory.
@brentsimmons makes total sense!