(kə·man′dər, -män′-) noun
1. One in command; a military leader.
2. In the U.S. Army, the commanding officer of a post or unit.
3. In the U.S. Navy, an officer ranking next above a lieutenant commander and next below a captain: equivalent in rank to a lieutenant colonel in the U.S. Army.
—lieutenant commander In the U.S. Navy, an officer ranking next above a lieutenant and next below a commander: equivalent in rank to a major in the U.S. Army.

(kə·man′dər, -män′-) noun
1. The chief officer of various orders, as Knights Templar, Grand Army posts, etc.
2. A member of a higher class in certain orders, as of knighthood.