The Collaborative International Dictionary of English v.0.48:

Cadre \Ca"dre\, n. [F. cadre, It. quadro square, from L.
   quadrum, fr. quatuor four.] (Mil.)
   The framework or skeleton upon which a regiment is to be
   formed; the officers of a regiment forming the staff.
   [Written also cader.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

cadre
    n 1: a small unit serving as part of or as the nucleus of a
         larger political movement [syn: cell, cadre]
    2: a nucleus of military personnel capable of expansion

Moby Thesaurus II by Grady Ward, 1.0:

102 Moby Thesaurus words for "cadre":
   KP, army, army group, battalion, battery, battle group, board,
   board of directors, board of regents, board of trustees, brigade,
   bunch, cabal, cabinet, camarilla, case, casement, casing, cell,
   charmed circle, chassis, circle, clan, clique, closed circle,
   cohort, column, combat command, combat team, company, corps,
   coterie, council, crew, crowd, detachment, detail, directorate,
   directory, division, doorframe, elite, elite group, executive arm,
   executive committee, executive hierarchy, fabric, field army,
   field train, file, flying column, frame, framework, framing,
   garrison, governing board, governing body, group, infrastructure,
   ingroup, inner circle, interlocking directorate, junta, junto,
   kitchen police, lattice, latticework, legion, management, maniple,
   mob, organization, outfit, phalanx, picture frame, platoon, posse,
   rank, regiment, ring, sash, section, set, shell, skeleton, squad,
   squadron, steering committee, tactical unit, task force,
   the administration, the brass, the executive, the people upstairs,
   top brass, train, troop, unit, we-group, window case, window frame,
   wing



The Free On-line Dictionary of Computing (30 December 2018):

CADRE

    The US software engineering vendor which merged
   with Bachman Information Systems to form Cayenne Software
   in July 1996.

   (1998-02-08)