(uncountable) Canis lupus arctos; A subspecies of the grey wolf, living in the Canadian Arctic Archipelago, including once Greenland, that is all-white. / (countable) An individual of the subspecies.

The island archipelago forming the northernmost extent of North America, less the Greenland island cluster, lying to the north of mainland Canada; forming the northernmost portion of Canada.

Ellipsis of Canadian Arctic Archipelago. / The North American arctic archipelago; Canadian Arctic Archipelago and Greenland

(anatomy) The position of a vertebra enclosing and protecting the heart and other viscera.

(religion) A chief or major heresy.

(religion) Highly heretical; being or relating to arch-heresy.

plural of arch-heresy

A landmark in Central London which lends its name to the surrounding area.

An arch less than a semicircle.

(architecture) A form of architecture where buildings are designed to allow parts of the structure to move, without reducing their overall integrity.