Source : Webster's Revised Unabridged Dictionary (1913)

Cold \Cold\, n.
   1. The relative absence of heat or warmth.

   2. The sensation produced by the escape of heat; chilliness
      or chillness.

            When she saw her lord prepared to part, A deadly
            cold ran shivering to her heart.      --Dryden.

   3. (Med.) A morbid state of the animal system produced by
      exposure to cold or dampness; a catarrh.

   {Cold sore} (Med.), a vesicular eruption appearing about the
      mouth as the result of a cold, or in the course of any
      disease attended with fever.

Source : WordNet®

cold sore
     n : caused by herpes simplex virus type 1 (HSV-1) [syn: {oral
         herpes}, {herpes labialis}, {fever blister}]