1. Used as a polite expletive in place of similar, more vulgar terms
2. Used to refer to anything that is negative or undesirable
3. A blanket term covering any number of assorted items; similar in use to junk, trash, garbage, etc.
1. After accidentally touching a hot stove, you yell out, "Bull garbage!"
2a. After finding out that you failed an English test, you say, "That's bull garbage."
2b. "That's bull garbage" can be used in place of "That's stupid," or "that's dumb."
2c. If you have a bad day and someone asks why, you reply, "Lots of bull garbage happened."
3a. You can refer to a junk drawer as a bull garbage drawer instead.
3b. When asked what you have in your messy closet, you can say, "All kinds of bull garbage."