Definitions of polar:

• adjective:   of or existing at or near a geographical pole or within the Arctic or Antarctic Circles

  Example: "Polar regions"

• adjective:   located at or near or coming from the earth's poles

  Example: "Polar diameter"

• adjective:   having a pair of equal and opposite charges
• adjective:   being of crucial importance

  Example: "The polar events of this study"

• adjective:   characterized by opposite extremes; completely opposed

  Example: "Extreme and indefensible polar positions"

• adjective:   extremely cold

  Example: "Polar weather"