sedate (adj.) Look up sedate at Dictionary.com
"calm, quiet," 1660s, from Latin sedatus "composed, moderate, quiet, tranquil," past participle of sedare "to settle, calm," causative of sedere "to sit" (see sedentary). Related: Sedately.
sedate (v.) Look up sedate at Dictionary.com
"treat with sedatives," 1945, a back-formation from the noun derivative of sedative (adj.). The word also existed 17c. in a sense "make calm or quiet." Related: Sedated; sedating.