Definition of Klondike
1a tributary of the Yukon River, in Yukon Territory, northwestern Canada, that rises in the Ogilvie Mountains and flows west for 100 miles (160 km) to join the Yukon at Dawson. It gave its name to the surrounding region, which became famous when gold was found in nearby Bonanza Creek in 1896. [as noun] a source of valuable material.
2 [as noun] chiefly
North American a form of the card game patience or solitaire.