Woo in my opinion, is any ''theory'' that can't be tested (proven) in a controlled setting, where general acceptance is reached by the overall science community. Although, long-accepted theories probably started out as ''woo'' ...until they gained acceptance. Hence, I'd imagine Charles Darwin for example, was probably viewed by his peers with raised eyebrows, when he first introduced his ideas about evolution. Spirituality/faith/religion is a different thing altogether, because it is subjective. It will always be subjective, even if it's objective truth for me, or anyone else who has particular faith views.