Woo is a colloquial, catch all term for nonsense. Made popular by James Randi in his book Flim Flam. It’s the word a lot of skeptics use to refer to alternative medicine and psychics. We’ll probably use it a few times in these facts this year.
It includes pseudoscience in all its glorious forms, bad medical treatments, beliefs in non-scientific things as facts and errors and mistakes compounded by poor logic and unreasonable conclusions