/
lɛfˈtɛnənt/
n.
    - a deputy or substitute acting for a superior.
 - a rank of officer in the British army, above second lieutenant and below captain.
 - a rank of officer in the navy, above sub lieutenant and below lieutenant commander.
 - (in the US) a police officer next in rank below captain.
 
Derivative
- lieutenancy n. 
(pl. lieutenancies)
. 
Etymology
ME: from OFr. (see lieu, tenant).