The Collaborative International Dictionary of English v.0.48:

Pursuit \Pur*suit"\, n. [F. poursuite, fr. poursuivre. See
   Pursue, v. t.]
   1. The act of following or going after; esp., a following
      with haste, either for sport or in hostility; chase;
      prosecution; as, the pursuit of game; the pursuit of an
      enemy. --Clarendon.
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            Weak we are, and can not shun pursuit. --Shak.
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   2. A following with a view to reach, accomplish, or obtain;
      endeavor to attain to or gain; as, the pursuit of
      knowledge; the pursuit of happiness or pleasure.
      [1913 Webster]

   3. Course of business or occupation; continued employment
      with a view to same end; as, mercantile pursuits; a
      literary pursuit.
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   4. (Law) Prosecution. [Obs.]
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            That pursuit for tithes ought, and of ancient time
            did pertain to the spiritual court.   --Fuller.
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   Curve of pursuit (Geom.), a curve described by a point
      which is at each instant moving towards a second point,
      which is itself moving according to some specified law.
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WordNet (r) 3.0 (2006):

pursuit
    n 1: the act of pursuing in an effort to overtake or capture;
         "the culprit started to run and the cop took off in
         pursuit" [syn: pursuit, chase, pursual, following]
    2: a search for an alternative that meets cognitive criteria;
       "the pursuit of love"; "life is more than the pursuance of
       fame"; "a quest for wealth" [syn: pursuit, pursuance,
       quest]
    3: an auxiliary activity [syn: avocation, by-line, hobby,
       pursuit, sideline, spare-time activity]
    4: a diversion that occupies one's time and thoughts (usually
       pleasantly); "sailing is her favorite pastime"; "his main
       pastime is gambling"; "he counts reading among his
       interests"; "they criticized the boy for his limited
       pursuits" [syn: pastime, interest, pursuit]

Moby Thesaurus II by Grady Ward, 1.0:

102 Moby Thesaurus words for "pursuit":
   accomplishment, activity, aim, area, art, avocation, bag, business,
   butt, by-end, by-purpose, calling, career, career building,
   careerism, chasing, chevy, chivy, craft, cup of tea, destination,
   dogging, employment, end, end in view, field, final cause,
   following, forte, game, goal, handicraft, heeling, hobby, hounding,
   hunt, hunting, interest, job, lifework, line, line of business,
   line of work, long suit, looking for, main interest, manner, mark,
   metier, mission, mystery, number, object, object in mind,
   objective, obtaining, occupation, pastime, pet subject, practice,
   prey, profession, pursual, pursuance, pursuing, quarry, quest,
   quintain, racket, reaching, reason for being, search, searching,
   seeking, sequel, sequence, series, shadowing, specialism,
   speciality, specialization, specialty, stalking, strong point,
   style, tailing, target, technicality, teleology, thing, tracing,
   tracking, trade, trailing, type, ultimate aim, vocation, walk,
   walk of life, way, weakness, work