Another example of etymology folklore. I listened to someone explaining that they loved the word grouse meaning ‘excellent’, which was interesting because I thought grouse might have been a word that was no longer in use. The origin of the word then offered was that it comes from grouse, the bird, because these birds were owned by the rich and were therefore excellent. We are all aware of the popularity of grouse hunting with the British aristocracy.
The only problem with this is that the word is an Australianism – the British don’t use it in this sense at all. It makes its appearance in Australian English in the 1920s, at which time grouse hunting was hardly a popular sport in Australia.
The best guess as to its origin is that it derives from a Scottish and Northern English dialect word, crouse, pronounced [kroos], meaning ‘merry and cheerful’, so I’m feeling crouse means 'I am feeling very good'. From Scottish crouse it is a small step to Australian English grouse. Scottish English has made quite a contribution to Australian English, so this is quite believable. The link to the bird makes a good story but sadly is not true.