ADJECTIVE (3)

1. properly or sufficiently qualified or capable or efficient;
- Example: "a competent typist"

2. adequate for the purpose;
- Example: "a competent performance"

3. legally qualified or sufficient;
- Example: "a competent court"
- Example: "competent testimony"

The Collaborative International Dictionary of English v.0.48:

Competent \Com"pe*tent\ (k[o^]m"p[-e]*tent; 94), a. [F.
   comp['e]tent, p. pr. of comp['e]ter to be in the competency
   of, LL. competere to strive after together, to agree with;
   hence, to be fit. See Compete.]
   1. Answering to all requirements; adequate; sufficient;
      suitable; capable; legally qualified; fit. "A competent
      knowledge of the world." --Atterbury. "Competent age."
      --Grafton. "Competent statesmen." --Palfrey. /"A competent
      witness." --Bouvier.
      [1913 Webster]

   2. Rightfully or properly belonging; incident; -- followed by
      to. [Rare, except in legal usage.]
      [1913 Webster]

            That is the privilege of the infinite Author of
            things, . . . but is not competent to any finite
            being.                                --Locke.

   Syn: See Qualified.
        [1913 Webster]

WordNet (r) 3.0 (2006):

competent
    adj 1: properly or sufficiently qualified or capable or
           efficient; "a competent typist" [ant: incompetent]
    2: adequate for the purpose; "a competent performance"
    3: legally qualified or sufficient; "a competent court";
       "competent testimony" [ant: incompetent, unqualified]

Moby Thesaurus II by Grady Ward, 1.0:

119 Moby Thesaurus words for "competent":
   OK, able, absolute, acceptable, actionable, adapted, adept,
   adequate, adjusted, all right, ample, applicable, ascendant,
   au fait, authoritarian, authoritative, authorized, autocratic,
   barely sufficient, capable, checked out, clothed with authority,
   comfortable, commanding, commensurate, consequential, considerable,
   constitutional, controlling, corresponding, decent, dominant, due,
   duly constituted, effective, effectual, efficacious, efficient,
   eminent, empowered, enough, equal to, ex officio, finished, fit,
   fitted, fitted for, good, good enough, governing, great, hegemonic,
   hegemonistic, imperative, important, influential, journeyman,
   judicial, juridical, just, justiciable, kosher, lawful, lawmaking,
   leading, legal, legislative, legit, legitimate, licit, masterly,
   mighty, minimal, minimum, momentous, monocratic, official, okay,
   plenty, plenty good enough, polished, potent, powerful, preeminent,
   prepared, prestigious, productive, proficient, prominent, proper,
   proportionate, puissant, qualified, ranking, rightful, ruling,
   sanctioned, satisfactory, senior, statutory, substantial,
   sufficient, sufficient for, sufficing, suitable, suited, superior,
   supreme, totalitarian, up to, up to snuff, valid, weighty,
   well-fitted, well-qualified, well-suited, wicked, within the law,
   worthy