sedative /sed″ətiv/ [L, sedatio, soothing] , 1. adj., pertaining to a substance, procedure, or measure that has a calming effect. 2. n., an agent that decreases functional activity, diminishes irritability, and allays excitement. Some sedatives have a general effect on all organs; others principally affect the activities of the heart, stomach, intestines, nerve trunks, respiratory system, or vasomotor system. See also sedative-hypnotic.
