This term was first seen on an episode of The Big Bang Theory titled "The Bus Pants Utilization".
Leonard: What the hell are bus pants?
Sheldon: They are pants one wears over one's regular pants when one sits on bus seats that other people have previously sat on.
British English uses the term "bus trousers".
- "All right, I suppose I'll go put on my bus pants."
- "What the heck are bus pants?"
- "They are pants one wears over one's regular pants when one sits on bus seats that another people have previously sat on."
-- The Big Bang Theory Season 4 Episode 12 (6 January 2011).
- "Hey, I am not able to drive you to work today."
- "Don't worry, I'll just put on my bus pants and use a bus."
In a bus, referring to a man with two pants on.
- "Look at that man. What is he wearing?"
- "Bus pants, obviously."