NOUN (1)

1. a means to an end; not necessarily a principled or ethical one;


ADJECTIVE (2)

1. serving to promote your interest;
- Example: "was merciful only when mercy was expedient"

2. appropriate to a purpose; practical;
- Example: "in the circumstances it was expedient to express loyalty"

The Collaborative International Dictionary of English v.0.48:

Expedient \Ex*pe"di*ent\a. [L. expediens, -entis, p. pr. of
   expedire to be expedient, release, extricate: cf. F.
   exp['e]dient. See Expedite.]
   1. Hastening or forward; hence, tending to further or promote
      a proposed object; fit or proper under the circumstances;
      conducive to self-interest; desirable; advisable;
      advantageous; -- sometimes contradistinguished from
      right or principled.
      [1913 Webster]

            It is expedient for you that I go away. --John xvi.
                                                  7.
      [1913 Webster]

            Nothing but the right can ever be expedient, since
            that can never be true expediency which would
            sacrifice a greater good to a less.   --Whately.
      [1913 Webster]

   2. Quick; expeditious. [Obs.]
      [1913 Webster]

            His marches are expedient to this town. --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Expedient \Ex*pe"di*ent\, n.
   1. That which serves to promote or advance; suitable means to
      accomplish an end.
      [1913 Webster]

            What sure expedient than shall Juno find,
            To calm her fears and ease her boding mind?
                                                  --Philips.
      [1913 Webster]

   2. Means devised in an exigency; shift.

   Syn: Shift; contrivance; resource; substitute.
        [1913 Webster]

WordNet (r) 3.0 (2006):

expedient
    adj 1: serving to promote your interest; "was merciful only when
           mercy was expedient" [ant: inexpedient]
    2: appropriate to a purpose; practical; "in the circumstances it
       was expedient to express loyalty"
    n 1: a means to an end; not necessarily a principled or ethical
         one

Moby Thesaurus II by Grady Ward, 1.0:

199 Moby Thesaurus words for "expedient":
   action, ad hoc measure, advantageous, advisable, agency, answer,
   applicable, appropriate, apropos, art, artful dodge, artifice,
   auspicious, banausic, becoming, befitting,
   behind-the-scenes influence, beneficial, benevolent, blind, bon,
   bonny, braw, bueno, capital, chicanery, cogent, commendable,
   commodious, congruous, conspiracy, contrivance, convenient,
   correct, countermove, coup, course of action, craft, cute trick,
   deceit, decent, demarche, dernier ressort, design, desirable,
   device, devices, dodge, effective, effort, elegant, employable,
   estimable, excellent, expediency, expedients, fair, fakement,
   famous, favorable, feasible, feint, felicitous, fetch, fine, fit,
   fitten, fitting, fortunate, fructuous, functional, gambit, game,
   gimmick, going between, good, good for, goodly, grand, grift,
   happy, healthy, helpful, hope, improvisation, influence,
   instrument, instrumentality, intermediation, intrigue, judicious,
   jugglery, jury-rig, jury-rigged expedient, kind, knavery,
   last expedient, last resort, last shift, laudable, likely,
   little game, lucky, machination, machinery, makeshift, maneuver,
   maneuvering, maneuvers, manipulation, means, measure, mechanism,
   mediation, medium, meet, move, nice, noble, of general utility,
   of help, of service, of use, opportune, pertinent, pis aller,
   pleasant, plot, ploy, politic, political influence, possible,
   practicable, practical, pragmatic, pragmatical, profitable, proper,
   propitious, providential, prudent, racket, recommendable,
   recommended, recourse, red herring, refuge, regal, resort,
   resource, right, ripe, royal, ruse, scheme, seasonable, seemly,
   service, serviceable, shake-up, shift, skillful, sleight, solution,
   sortable, sound, splendid, step, stopgap, stratagem, strategy,
   stroke, stroke of policy, substitute, subterfuge, suitable, tactic,
   tactical, tactical maneuvers, tactics, temporary expedient, timely,
   to be desired, trick, trickery, trump, useful, utilitarian, valid,
   very good, virtuous, well-timed, wile, wily device, wire-pulling,
   wise, working hypothesis, working proposition, worthwhile