Often been wondering what these are in US politics. Forever hearing on progs like "The West Wing" or where there are political shinnanigans, "He's a member of the Multilateral Lower Swing Swivel Misappropriation Oversight Committee".

Is this a group of people who get together in order not to notice, or forget stuff?

Q. "Why didn't you bring your briefcase?"
A. "Sorry. It was an oversight"

Or (more likely) a group that supervises or OVERSEES something or other that's going on? In which case the word seems a bit daft. Like wouldn't "supervisory" be better.

"The men work better under my supervision" sounds OK

"The men work better under my oversight" sounds daft, and suggests that they're doing well despite my lack of attention!