Commander

1. n. A heavy beetle or wooden mallet, used in paving, in sail lofts, etc.
2. n. A chief; one who has supreme authority; a leader; the chief officer of an army, or of any division of it.
3. n. An officer who ranks next below a captain, — ranking with a lieutenant colonel in the army.
4. n. The chief officer of a commandery.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.