This word, in its Australian version, is quite well-known to me.
As it happens, one of the example quotes for it in the
Australian National Dictionary is from a book my father wrote: "I was real arsy to pick up a job here." (
No Sunlight Singing (1960), by Joe Walker)
The Australian dictionaries all have the Australian meaning, lucky. The
Oxford Dictionary of English has the Australian usage and the British one mentioned by cmh, "bad-tempered or uncooperative". The
Collins Dictionary has the British one. So the word is in several dictionaries. It is also in use: there are plenty of examples of the word in the Aussie sense on
Whirlpool, a popular Australian forum site. And there are quite a few examples on the
Guardian website of the British usage.
From what I can see, the spellings
arsey and
arsy are often used, but
arsie rarely if ever. So I think I should add
arsey and
arsy, along with
arsier and
arsiest, which are the inflected forms according to the Oxford.
I don't think
arsey /
arsy would be known to many Americans, so the added entries must be classed as rare.