The Collaborative International Dictionary of English v.0.48:

Brisk \Brisk\ (br[i^]sk), a. [Cf. W. brysg, fr. brys haste,
   Gael. briosg quick, lively, Ir. broisg a start, leap, jerk.]
   1. Full of liveliness and activity; characterized by
      quickness of motion or action; lively; spirited; quick.
      [1913 Webster]

            Cheerily, boys; be brick awhile.      --Shak.
      [1913 Webster]

            Brisk toil alternating with ready ease. --Wordworth.
      [1913 Webster]

   2. Full of spirit of life; effervesc?ng, as liquors;
      sparkling; as, brick cider.
      [1913 Webster]

   Syn: Active; lively; agile; alert; nimble; quick; sprightly;
        vivacious; gay; spirited; animated.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Brisk \Brisk\, v. t. & i. [imp. & p. p. Bricked; p. pr. & vb.
   n. Bricking.]
   To make or become lively; to enliven; to animate; to take, or
   cause to take, an erect or bold attitude; -- usually with up.
   [1913 Webster]

WordNet (r) 3.0 (2006):

brisk
    adj 1: quick and energetic; "a brisk walk in the park"; "a
           lively gait"; "a merry chase"; "traveling at a rattling
           rate"; "a snappy pace"; "a spanking breeze" [syn:
           alert, brisk, lively, merry, rattling,
           snappy, spanking, zippy]
    2: imparting vitality and energy; "the bracing mountain air"
       [syn: bracing, brisk, fresh, refreshing,
       refreshful, tonic]
    3: very active; "doing a brisk business"
    v 1: become brisk; "business brisked up" [syn: brisk, brisk
         up, brisken]

Moby Thesaurus II by Grady Ward, 1.0:

177 Moby Thesaurus words for "brisk":
   Siberian, active, activist, activistic, acute, adroit, aeolian,
   aggressive, airish, airy, algid, alive, animated, arctic,
   astringent, below zero, biting, bitter, bitterly cold, blasty,
   bleak, blowy, blustering, blusterous, blustery, boreal, bouncing,
   bouncy, bracing, breezy, brief, brumal, bubbly, burning, busy,
   caustic, cheering, chill, chilly, chipper, cold, cold as charity,
   cold as death, cold as ice, cold as marble, cometary, cool,
   cordial, crisp, crispy, curried, cutting, drafty, dynamic,
   ebullient, effervescent, energetic, energizing, enterprising,
   enthusiastic, exhilarating, favonian, flashing, flawy, fleet,
   flickering, forceful, forcible, freezing, freezing cold, fresh,
   frigid, frisky, full of go, full of life, full of pep, gelid,
   glacial, go-go, gusty, hearty, hibernal, hiemal, high-seasoned,
   hot, hot as pepper, hyperborean, ice-cold, ice-encrusted, icelike,
   icy, impetuous, incisive, inclement, intense, invigorating, keen,
   kinetic, live, lively, living, lusty, mercurial, meteoric,
   mettlesome, militant, nimble, nipping, nippy, numbing, penetrating,
   peppery, peppy, perky, pert, piercing, pinching, puffy, quick,
   quicksilver, racy, raw, refreshful, refreshing, regaling, rigorous,
   robust, rousing, seasoned, severe, sharp, short, short and sweet,
   short-term, short-termed, sleety, slushy, smacking, snappy,
   spanking, speedy, spiced, spicy, spirited, sprightly, spry,
   squally, stabbing, steady, stimulating, stinging, stone-cold,
   strenuous, strong, subzero, supercooled, swift, take-charge,
   take-over, tangy, tonic, trenchant, vibrant, vigorous, vivacious,
   vivid, volant, windy, winterbound, winterlike, wintery, wintry,
   with a kick, zestful, zesty, zingy, zippy