[1] : The Collaborative International Dictionary of English v.0.48

sedate \sedate"\, a. l. sedatus, p. p. of sedare, sedatum, to
   allay, calm, causative of sedere to sit. see sit.
   undisturbed by passion or caprice; calm; tranquil; serene;
   not passionate or giddy; composed; staid; as, a sedate soul,
   mind, or temper.
   1913 webster

         disputation carries away the mind from that calm and
         sedate temper which is so necessary to contemplate
         truth.                                   --i. watts.
   1913 webster

         whatsoever we feel and know
         too sedate for outward show.             --wordsworth.
   1913 webster

   syn: settled; composed; calm; quiet; tranquil; still; serene;
        unruffled; undisturbed; contemplative; sober; serious.
        1913 webster -- sedate"ly, adv. -- sedate"ness,
        n.
        1913 webster
see also:
sit sedate"ly sedate"ness 

[2] : WordNet (r) 2.0

sedate
     adj 1: characterized by dignity and propriety syn: staid
     2: dignified and somber in manner or character and committed to
        keeping promises; "a grave god-fearing man"; "a quiet
        sedate nature"; "as sober as a judge"; "a solemn promise";
        "the judge was solemn as he pronounced sentence" syn: grave,
         sober, solemn
     v : cause to be calm or quiet as by administering a sedative to;
         "the patient must be sedated before the operation" syn:
         calm, tranquilize, tranquillize, tranquillise
         ant: stimulate
see also:
staid grave sober solemn calm tranquilize 
tranquillize tranquillise stimulate 

[3] : Moby Thesaurus II by Grady Ward, 1.0

84 moby thesaurus words for "sedate":
   anesthetize, aristocratic, august, calm, collected, composed,
   controlled, conventional, cool, courtly, decorous, demure,
   detached, dignified, dispassionate, dope, drug, earnest, entrance,
   even-tempered, formal, frowning, fussy, grand, grave, grim,
   grim-faced, grim-visaged, hypnotize, imperturbable, imposing,
   kingly, long-faced, lordly, lull to sleep, magisterial, magnetize,
   majestic, mesmerize, moderate, narcotize, no-nonsense, noble,
   old-fashioned, peaceful, placid, prim, princely, proper, prudish,
   put to sleep, put under, queenly, refined, regal, rock to sleep,
   royal, seemly, serene, serious, sober, sober-minded, sobersided,
   solemn, somber, staid, stately, statuesque, stiff, stone-faced,
   straight-faced, strait-laced, temperate, thoughtful, trance,
   tranquil, undisturbed, unflappable, unperturbed, unruffled,
   unsmiling, venerable, weighty, worthy

Sedate >> S Words
Sedate, definition of term: Sedate
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