a small, polished, flat surface, usually in the shape of a polygon, such as one of the surfaces of a cut gem.

a smooth, flat surface cut on a fragment of rock by the action of water, windblown sand, etc.

aspect; phase:

Architecture. any of the faces of a column cut in a polygonal form.

Zoology. one of the corneal lenses of a compound arthropod eye.

Anatomy. a small, smooth, flat area on a hard surface, especially on a bone.

Dentistry. a small, highly burnished area, usually on the enamel surface of a tooth, produced by abrasion between opposing teeth in chewing.

to cut facets on.