run to earth, to

to find something after a search. Lisa finally ran her long-lost cousin to earth in Paris. After months of searching, I ran a copy of Jim's book to earth.

Also, run to ground. Track down, find, as in Somehow we have to run those relatives of hers to earth, or It won't be easy, but I'm sure we can run that jewelry to ground. This expression comes from hunting, where hounds run their quarry to the earth or ground, that is, to their lair. Its figurative use dates from the mid-1800s.

To find. The term comes from hunting, when the hounds run their quarry to its “earth” or “lair.” This meaning of “earth” survives only in the cliché, which had been transferred to tracking down just about anything or anyone by the mid-nineteenth century. The OED cites an 1888 issue of The Spectator: “All the men who helped to run to earth the various members of the Ruthven family.”