putrefy - Dictionary definition and meaning for word putrefy
think of purefy(purify-to make pure). now put a t in the middle..this makes it opposite. that is to rot.
put(Keep)+ refy(refined/fresh)but food kept outside for some days would generally get decayed or rot
put + re(ra) +fy(fly/flies) in order to rot the food which give foul odor