For clarity, a 'stoater', at least in my part of the world, is a wonderfully versatile word, which can be applied to a number of things.
A few examples:
Anyone who saw Ronaldinho score that audacious goal on Tuesday night? That was a stoater.
My pal's new telly. Flat screen, 42", lovely display - stoater!
The above are examples of positive usage.
When it comes to describing young women (I've never heard girls or gay people use it, think it's a hetero, male thing) things can be a little more confusing.
For example, one may be heard asking:
"Huv ye seen that Halle Berry? Right wee stoater, so she is!"
Again this is positive. On the other hand, you may also overhear:
"Huv ye seen that Roseanne Barr? Right big stoater, so she is!"
Obviously negative.
I believe the origin comes from the verb; to 'stoat'. This generally means to 'bounce' or 'hit', as far as I'm aware.
One can stoat a ball, off a wall. Incidentally, on can be referred to as 'stoat-the-baw'. This is usually but not always derogatory.
It would only be used in reference the the animal, the stoat, if said stoat was particularly cute, agile, fast, etc.
e.g. "That wee stoat's a right wee stoater."
I hope that clears up any misunderstanding.
