guitar rage
1. When someone tries to touch a guitarist's guitar without permission and they go into a state of extreme rage and try to murder you.  This is commonly followed up with the petting of the guitar and singing of lullabies to it.

2. When you insult someone's guitar playing and they go ape on you.

3. When a wielder is rocking out intensely and receives wounds from his playing but keeps rocking out anyways.

4. When you insult a wielder's actual guitar and they try to kill you.
1. Dude, I tried to touch John's guitar and he had a total fit of guitar rage!  I barely survived.

2. Do not anger the guitar rage monkey in me!!!! Beware!

3. Did you see John's guitar rage tonight?  His fingers were bleeding and he bashed his head open with his headstock, but he kept playing!

4. I called John on his icky guitar and he had a fit of guitar rage.  That's what the cast is for.