WordNet (r) 3.0 (2006):

commissar
    n 1: an official of the Communist Party who was assigned to
         teach party principles to a military unit [syn:
         commissar, political commissar]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "commissar":
   Simon Legree, absolute monarch, absolute ruler, alderman,
   all-powerful ruler, archon, arrogator, autarch, autocrat, bailie,
   burghermaster, burgomaster, cabinet member, cabinet minister,
   caesar, chancellor, city councilman, city father, city manager,
   commissary, commissionaire, commissioner, councillor, councilman,
   councilwoman, county commissioner, county supervisor, czar,
   delegate, despot, dictator, disciplinarian, driver, duce, elder,
   emissary, envoy, hard master, headman, herald, induna, legate,
   legislator, lord mayor, magistrate, maire, martinet, mayor,
   messenger, minister, minister of state, oligarch, oppressor,
   pharaoh, portreeve, reeve, secretary, secretary of state,
   selectman, slave driver, stickler, supervisor, syndic, tyrant,
   undersecretary, usurper, warden, warlord



Bouvier's Law Dictionary, Revised 6th Ed (1856):

COMMISSARY. An officer whose principal duties are to supply the army with
provisions.
     2. The Act of April 14, 1818, s. 6, requires that the president, by and
with the consent of the senate, shall appoint a commissary general with the
rank, pay, and emoluments of colonel of ordnance, and as many assistants, to
be taken from the sub-alterns of the line, as the service may require. The
commissary general and his assistants shall perform such duties, in the
purchasing and issuing of rations to the armies of the United States, as the
president may direct. The duties of these officers are further detailed in
the subsequent sections of this act,, and in the Act of March 2, 1821.