The Collaborative International Dictionary of English v.0.48:

Hockday \Hock"day`\, n. [Cf. AS. h[=o]cor mockery, scorn.]
   A holiday commemorating the expulsion of the Danes, formerly
   observed on the second Tuesday after Easter; -- called also
   hocktide. [Eng.] [Written also hokeday.]
   [1913 Webster]