\Why"-not`\, n.
A violent and peremptory procedure without any assigned
reason; a sudden conclusive happening. [Obs.]
      When the church Was taken with a why-not in the lurch.
                                               --Hudibras.
      This game . . . was like to have been lost with a
      why-not.                                 --Nug[ae]
                                               Antiq.