"calm, quiet, placid," usually of persons or temperaments, 1660s, from Latin sedatus "composed, moderate, quiet, tranquil," past participle of sedare "to settle, make calm," causative of sedere "to sit" (from PIE root *sed- (1) "to sit"). Related: Sedately; sedateness (1640s).
"treat with sedatives," by 1945, a verb to go with the noun derivative of sedative (adj.). The word also existed 17c. in English with a sense of "make calm or quiet." Related: Sedated (by 1953 as an adjective, "under the influence of a sedative drug"); sedating.
updated on April 06, 2022