Source : Webster's Revised Unabridged Dictionary (1913)

Dominion Day \Do*min"ion Day\
   In Canada, a legal holiday, July lst, being the anniversary
   of the proclamation of the formation of the Dominion in 1867.

Source : WordNet®

Dominion Day
     n : a legal holiday in Canada commemorating receiving Dominion
         status in 1867 [syn: {July 1}]