W.

Proper noun

 * 1) Wednesday.

Noun

 * 1) West.

Adjective

 * 1) Western.

Usage notes
This is the customary abbreviation of this term as used in case citations. See, e.g., The Bluebook: A Uniform System of Citation, Nineteenth Edition (2010), "Case Names and Institutional Authors in Citations", Table T6, p. 430-431.