Definition of "ferret"

The most challenging documentary discoveries were made by a tenacious archival ferret, Dr Antonio Bertoletti. In 1879 he published his findings in a slim, refreshingly dry volume, Francesco Cenci e la sua Famiglia.

1998 July 2, Charles Nicholl, “Screaming in the Castle”, in London Review of Books, volume XX, number 13

Master Fer! I'll fer him, and firk him, and ferret him.

1599, William Shakespeare, “The Life of Henry the Fift”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act IV, scene iv]

I confess that we were so unpopular with the outrageous mob, that I only got away from England at the risk of being ducked to death, and that Cly was so ferreted up and down, that he never would have got away at all but for that sham.

1859, Charles Dickens, A Tale of Two Cities

He had been piqued by the failure of all his endeavors to ferret out the assassins.

1842, Edgar Alan Poe, The Mistery of Marie Roget

She ferreted in her bag; then held it up mouth downwards; then fumbled in her lap, all so vigorously that Charles Steele in the Panama hat suspended his paint-brush.

1922, Virginia Woolf, chapter 1, in Jacob's Room

red tape and green ferret

1852 March – 1853 September, Charles Dickens, Bleak House, London: Bradbury and Evans, […], published 1853