[1] : The Collaborative International Dictionary of English v.0.48

colonel \colo"nel\, n. f. colonel, it. colonello, prop., the
   chief or commander of a column, fr. colonna column, l.
   columna. see column. mil.
   the chief officer of a regiment; an officer ranking next
   above a lieutenant colonel and next below a brigadier
   general.
   1913 webster
see also:
column 

[2] : WordNet (r) 2.0

colonel
     n : a commissioned military officer in the united states army or
         air force or marines who ranks above a lieutenant colonel
         and below a brigadier general

[3] : Moby Thesaurus II by Grady Ward, 1.0

51 moby thesaurus words for "colonel":
   adc, co, od, aide, aide-de-camp, brigadier, brigadier general,
   captain, chicken colonel, chief of staff, commandant, commander,
   commander in chief, commanding officer, commissioned officer,
   company officer, exec, executive officer, field marshal,
   field officer, first lieutenant, five-star general,
   four-star general, general, general officer, generalissimo,
   jemadar, junior officer, lieutenant, lieutenant colonel,
   lieutenant general, major, major general, marechal, marshal,
   officer, one-star general, orderly officer, risaldar,
   senior officer, shavetail, sirdar, staff officer, subahdar,
   subaltern, sublieutenant, the old man, the brass,
   three-star general, top brass, two-star general

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

colonel. an officer in the army, next below a brigadier general, bears this 
title. 

Colonel >> C Words
Colonel, definition of term: Colonel
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