I was passing a sign today that said Eyewash, meaning a place where one could wash an eye that had some foreign matter in it; a common thing in laboratories and factories. But the first impression I gained was of eyewash, meaning something close to poppycock or codswallop.
This set me to wondering what the origin of this term was; Green's Dictionary of Slang doesn't even include this as a headword. This source here suggests it is the verbal equivalent of a wink; is that so? Does anyone know more about it?
Edit Sorry if this wasn't immediately apparent but it was the slang term I am most interested in.