The Collaborative International Dictionary of English v.0.48:

Kirk \Kirk\ (k[~e]rk), n. [Scot.; cf. Icel. kirkja, of Greek
   origin. See Church.]
   A church or the church, in the various senses of the word;
   esp., the Church of Scotland as distinguished from other
   reformed churches, or from the Roman Catholic Church. [Scot.]
   --Jamieson.
   [1913 Webster]

WordNet (r) 3.0 (2006):

kirk
    n 1: a Scottish church