WordNet sense 1 (an officer who is licensed to command a merchant ship):

master, skipper, sea captain

WordNet sense 2 (the leader of a group of people):

chieftain

WordNet sense 3 (a policeman in charge of a precinct):

police captain, police chief

WordNet sense 4 (the pilot in charge of an airship):

senior pilot

WordNet sense 5 (a dining-room attendant who is in charge of the waiters and the seating of customers):

headwaiter, maitre d', maitre d'hotel