peninsula in Nunavut, Canada: its N tip is the northernmost point of the North American mainland
See Boothia Peninsula in American Heritage Dictionary 4
(bo͞oˈthē-ə)
The northernmost tip of the North American mainland, in central Nunavut, Canada. It is connected with the Canadian mainland by the narrow Isthmus of Boothia and separated from Baffin Island to the east by the Gulf of Boothia, an arm of the Arctic Ocean.