The Collaborative International Dictionary of English v.0.48:

Brigadier general \Brig`a*dier" gen"er*al\ [F. brigadier, fr.
   brigade.] (Mil.)
   An officer in rank next above a colonel, and below a major
   general. He commands a brigade, and is sometimes called, by a
   shortening of his title, simple a brigadier.
   [1913 Webster]

WordNet (r) 3.0 (2006):

brigadier
    n 1: a general officer ranking below a major general [syn:
         brigadier, brigadier general]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "brigadier":
   ADC, CO, OD, aide, aide-de-camp, brigadier general, captain,
   chicken colonel, chief of staff, colonel, 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