cold [AS, kald] , 1. adj., the absence of heat. 2. n., a contagious viral infection of the upper respiratory tract, usually caused by a strain of rhinovirus. It is characterized by rhinitis, tearing, low-grade fever, and malaise and is treated symptomatically with rest, mild analgesia, decongestants, and increased fluid intake. Also called common cold. Compare influenza. 3. adj., a distant method of relating; not friendly.