com·mand·er / kəˈmandər/ (abbr.: Comdr.) • n. 1. a person in authority, esp. over a body of troops or a military operation. ∎ a naval officer of high rank, in particular (in the U.S. Navy or Coast Guard) an officer ranking above lieutenant commander and below captain. ∎ (in certain metropolitan police departments) the officer in charge of a division, district, precinct, or squad.2. a member of a higher class in some orders of knighthood.DERIVATIVES: com·mand·er·ship / -ˌship/ n.