lieutenant lieutenant /luːˈtɛnənt/

noun

1. () (military) a commissioned military officer  ( lieutenant )
   (military) a commissioned military officer
     The lieutenant governor supported the governor in managing state affairs.
   The lieutenant governor supported the governor in managing state affairs.
   
   
2. () An officer in a police force  ( police lieutenant , lieutenant )
   an officer in a police force
     The lieutenant led his platoon with discipline and courage.
   The lieutenant led his platoon with discipline and courage.
   
3. () An assistant with power to act when his superior is absent  ( deputy , lieutenant )
   an assistant with power to act when his superior is absent
   
4. (military) an officer holding a commissioned rank in the United States Navy or the United States Coast Guard; below lieutenant commander and above lieutenant junior grade  ( lieutenant )
   (military) an officer holding a commissioned rank in the United States Navy or the United States Coast Guard; below lieutenant commander and above lieutenant junior grade