The Collaborative International Dictionary of English v.0.48:

Murnival \Mur"ni*val\, n. [Perh. fr. F. mornifle a game at
   cards.]
   In the game of gleek, four cards of the same value, as four
   aces or four kings; hence, four of anything. [Obs.] [Written
   also mournival.]
   [1913 Webster]