Polite euphemism used to replace a popular expletive, the exact meaning varies depending on context. Handy for use in workplaces where the management are uptight squares who stifle free speech.
To blaze, most commonly the chronic, but can also refer to the bomb tobacco.
I had just been involved in a rather large chuff session(the heady nuggets of course) on the booby bus when I grabbed a keystone to relieve my cottonmouth.