The Collaborative International Dictionary of English v.0.48:

Junta \Jun"ta\ (j[u^]n"t[.a]), n.; pl. Juntas (j[u^]n"t[.a]z).
   [Sp., fr. L. junctus joined, p. p. of jungere to join. See
   Join, and cf. Junto.]
   1. A council; a convention; a tribunal; an assembly; esp.,
      the grand council of state in Spain.
      [1913 Webster]

   2. A junto.
      [PJC]

   3. A small committee or group self-appointed to serve as the
      government of a country, usually just after a coup d'etat
      or revolution, and often composed primarily of military
      men. The term is used mostly in Latin American countries.
      [PJC]

WordNet (r) 3.0 (2006):

junta
    n 1: a group of military officers who rule a country after
         seizing power [syn: military junta, junta]

Moby Thesaurus II by Grady Ward, 1.0:

157 Moby Thesaurus words for "junta":
   Anschluss, British Cabinet, Sanhedrin, US Cabinet, addition,
   advisory body, affiliation, age group, agglomeration, aggregation,
   agreement, alliance, amalgamation, assembly, assimilation,
   association, band, battalion, bench, bevy, blend, blending, board,
   body, body of advisers, borough council, brain trust, brigade,
   bunch, cabal, cabinet, cadre, camarilla, cartel, cast, cell,
   centralization, chamber, charmed circle, circle, city council,
   clan, clique, closed circle, coalescence, coalition, cohort,
   combination, combine, combo, common council, company, complement,
   composition, confederacy, confederation, conference, congeries,
   conglomeration, congress, conjugation, conjunction, consolidation,
   conspiracy, consultative assembly, contingent, corps, coterie,
   council, council fire, council of ministers, council of state,
   council of war, county council, court, covey, crew, crowd,
   deliberative assembly, detachment, detail, diet, directory, divan,
   division, ecumenism, elite, elite group, embodiment, encompassment,
   enosis, faction, federalization, federation, fleet, fusion, gang,
   group, grouping, groupment, hookup, in-group, inclusion,
   incorporation, ingroup, inner circle, integration, junction, junto,
   kitchen cabinet, league, legislature, marriage, meld, melding,
   merger, mob, movement, out-group, outfit, pack, package,
   package deal, parish council, party, peer group, phalanx, platoon,
   posse, privy council, regiment, ring, salon, set, solidification,
   soviet, squad, stable, staff, string, syncretism, syndicate,
   syndication, syneresis, synod, synthesis, team, tie-up, tribe,
   tribunal, troop, troupe, unification, union, we-group, wedding,
   wing