offbeat
Nonconventional; different from the usual; odd.
Linguistics used to be an offbeat field, but nowadays every self-respecting university has a linguistics department.
search me
beats me
I don't know; how should I know? May be considered rude.
When I asked her what time it was, she said, "Search me, I have no watch."
When Elmer asked his wife if she knew why the new neighbors left their garage door open all night, she responded, "Search me."
When I asked Derek why his girlfriend wasn’t at the party yet, he said, "Beats me. I expected her an hour ago."