(geography) The part of the Earth between the geographical South Pole and the Antarctic Circle.

simple past tense and past participle of zero. Cf. also zeroized.

(firearms) The adjustment of a sight, exactly parallel to the axis of the bore of the gun to which it is attached.

(biology) an environment that allows the development of adaptive radiation

(cycling) A designated place along the course of a bicycle race where it is permitted for the riders to receive food and energy drinks from their team support personnel.

Any large portion of the Earth's land area which has a generally uniform climate and soil and therefore a high degree of uniformity in the composition of species; a number of different classifications have been proposed by different people.

(oceanography) That part of the deep body of an ocean or lake that receives insufficient sunlight for photosynthesis to be possible.

The part of the near-surface body of an ocean or lake that receives enough sunlight for photosynthesis to be possible.

(Mormonism) A territorial subdivision of The Church of Jesus Christ of Latter-day Saints consisting of several wards and, possibly, branches.

The forehead and nose considered together as a region of the face that can, in some people, produce excess sebum compared to other parts of the face.