Source : Webster's Revised Unabridged Dictionary (1913)

Haymaker \Hay"mak`er\, n.
   1. One who cuts and cures hay.

   2. A machine for curing hay in rainy weather.

Source : WordNet®

haymaker
     n 1: a farm machine that treats hay to cause more rapid and even
          drying [syn: {hay conditioner}]
     2: a hard punch that renders the opponent unable to continue
        boxing [syn: {knockout punch}, {KO punch}, {Sunday punch}]