When a person is about to fight and they want someone to hold them back. It’s basically saying hold me back like a belt holds up pants, or a seat belt holds up back.
When finance content creators rent out fancy cars and flexcash to seem richer than they really are in order to promote and sell their “get rich quick” courses.
The use of the word "blue" to refer to sexually explicit content was first recorded in Scotland in 1824. "Blue" meant "lewd" because prostitutes dressed in blue gowns.