Qualified Perceptions

Yes, but as with the definition of a sandwich, I'd have a hard time saying exactly what I think the difference is. I want to say that if it has the sort of collar you can wear a tie with, I would never call it a blouse, but I'm not sure that's 100% true. (It is true of, say, firstfrost's collared silk shirts.) If it's made of something heavy like denim or corduroy, I wouldn't call it a blouse. (If it's made to be worn by a man, in the 20th century, I would also not call it a blouse; but that begs the question of how I know it's made for a man.) If it has poofy sleeves, or lace on it, I'm likely to call it a blouse, but I own exceptions to this rule.