ferret out
Upper Intermediate (B2)informal
To find something hidden or secret by searching very hard until you discover it.
"The researcher managed to ferret out some fascinating details about the artist's early life."
Hear it in context

Corruption vs. Hope: Montenegro’s Turning Point | Focus on Europe
DW News · 1:01
but at first needs to ferret out corruption.

3 Steps To Seduce Any Woman Like A CIA Spy
Andrew Bustamante · 49:43
That's how you can start to ferret out whether somebody

We can't invent a robot better than these ferrets
Tom Scott · 14:37
And it’s not like you could shake the pipe to get the ferret out.

Martha Stewart Interview: Recipe for Entrepreneurial Success
Life Stories · 20:43
a lot of hard work to ferret out those good Investments so then the next