The Collaborative International Dictionary of English v.0.48:

Constabulary \Con*stab"u*la*ry\, a. [LL. constabularius an
   equerry. See Constable.]
   Of or pertaining to constables; consisting of constables.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Constabulary \Con*stab"u*la*ry\, n.
   The collective body of constables in any town, district, or
   country.
   [1913 Webster]

WordNet (r) 3.0 (2006):

constabulary
    n 1: the force of policemen and officers; "the law came looking
         for him" [syn: police, police force, constabulary,
         law]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "constabulary":
   Cheka, FBI, Gestapo, Interpol, MP, MVD, Mounties, NKVD, OGPU, RCMP,
   SP, Scotland Yard, bailiwick, bureau, commissariat, constablery,
   constablewick, county police, department, highway patrol,
   law enforcement agency, military police, ministry, municipality,
   office, police, police force, political police, posse,
   provincial police, riot police, secret police, secretariat,
   security force, sheriffalty, sheriffwick, shore patrol, shrievalty,
   special police, state police, tactical police, troopers,
   vigilance committee, vigilantes