Answer:
You use a knife to slice my head and weep beside me when I am dead.
What is so fragile that saying its name breaks it?
What is the word that even in plain sight remains hidden?
When it comes to me you go on red and stop on green.
Though desert men once called me God today men call me mad. For I wag my tail when I am angry. And growl when I am glad.
I flow from the Homerβs mouth when he sees doughnuts.