镇定剂
Tranquilizer \Tran"quil*i`zer\, Tranquillizer \Tran"quil*li`zer\ , n. One who, or that which, tranquilizes.
tranquilizer n : a drug used to reduce stress or tension without reducing mental clarity [syn: {tranquillizer}, {tranquilliser}, {antianxiety agent}, {ataractic drug}, {ataractic agent}, {ataractic}]