What is ceiling smear?

Just wondering, but some people talk about 'ceiling smear'. What is it? Does it degrade sound? How can it be corrected?
I have only one instance of ceiling smear in my listening area. Since then I have never again smacked a mosquito on white paint with a rolled up magazine.
I don't think it really degraded sound. but the visual effect was not good. Eventually I had to paint over it and the problem was solved. Does this answer your question or am I just bugging you?
snooker's post is prolly more informative than mine, :>) but 1st-reflections from the ceiling can be ameliorated w/acoustical panels, the same way ewe deal w/them from the side-walls: place the panel at the point where ewe could see the speakers from the listening-position if the panel was a mirror...

doug s.

I believe that "ceiling smear" is a term that refers to flavored cream cheese that has stuck to the ceiling when someone's child flings their bagel skyward...
But if the bagel sticks? Problem solved. Sound bagels.
Snooker - I'm sorry you don't like the visual. I myself have developed 'wall art,' a medium of expression wherein the pinnacle is to kill a bug (the best is a large moth) against a wall or ceiling while damaging it the least amount possible (but still having it stick). if it's all smashed up, that's not that great. i have a few keepers - moths that basically look untouched but are long dead and stuck to the wall. i love the visual. i'll admit, though, that most of my guests agree with you...