1. When capitalized as Arctic, it means the region that lies around the North Pole, inside the Arctic Circle; usually, regarded as including all areas within the Arctic Circle or all areas north of the tree line which includes the northernmost parts of Alaska, Canada, Scandinavia, and the Soviet Union, as well as Greenland.
2. When spelled as arctic, it refers to being extremely cold or found in, coming from, or associated with this region.

Most compound entries using this term may be spelled either as Arctic or arctic.

An air mass, cold aloft and extending to great heights, whose characteristics develop mostly in winter over arctic surfaces of ice and snow.

A large group of islands in northeastern Canada between the Canadian mainland and Greenland.

In the Northern Hemisphere, the parallel of latitude that is equal to the complement of the summer solstice; due to steady variations in the obliquity of the summer solstice, the position of the Arctic Circle is constantly changing.

The climate of a polar region; usually one that is too cold to allow the growth of trees.

The ill-defined polar convergence zone of the Northern Hemisphere.

An area, especially in the polar regions, having little or no vegetation due to extremely cold temperatures.

A carnivorous mammal of the dog family known for its thick, white winter coat as well as a gray phase.

Arctic adaptations include rounded ears, a short muzzle, and fur-covered footpads.

The semi-permanent, semi-continuous front between deeper, colder arctic air and shallower, less cold polar air of northern latitudes.

1. A condition in which visibility in the air is reduced in horizontal and slant directions but remains unimpeded vertically; encountered by aircraft over arctic regions.
2. A smog-like layer of haze observed in the Arctic atmosphere at certain times of the year, of unknown origin but thought to be caused by the transport of industrial pollutants from lower latitudes.

A weak high appearing on mean charts of sea-level pressure over the Arctic Basin during late spring, summer, and early autumn.

The relatively small intermediate water masses of the North Pacific and North Atlantic, respectively located north of a line between the Aleutian Islands and Japan and north of a line between Iceland and Labrador.

A light ice fog that appears as a mist of ice crystals.

A vast area of land (more than 19 million acres) in northeastern Alaska that is designated by the U.S. as a wildlife sanctuary.

The Arctic National Wildlife Refuge, or ANWR, is currently a focus of debate between those who argue that the entire area should be maintained as wilderness and those who argue that a portion of it (the Coastal Plain) should be opened to oil and gas explorations and production.

The Arctic Ocean is the smallest of the world's five oceans (after the Pacific Ocean, Atlantic Ocean, Indian Ocean, and the recently delimited [established boundaries] Southern Ocean): The Northwest Passage (U.S. and Canada) and Northern Sea Route (Norway and Russia) are two important seasonal waterways. A sparse network of air, ocean, river, and land routes circumscribes the Arctic Ocean.

The polar climate is characterized by persistent cold and relatively narrow annual temperature ranges; winters characterized by continuous darkness, cold and stable weather conditions, and clear skies; summers characterized by continuous daylight, damp and foggy weather, and weak cyclones with rain or snow.

Any sea ice that is more than one year old and more than three meters thick.

A steam fog rising from areas of open water within sea ice.

A fog that forms when water vapor mixes with air that is much colder than the vapor's source, as when very cold air drifts across warm water.

A description of areas above the timberline in mountainous northern regions.