lieutenant

noun
1
an officer of middle rank in the army, navy, or air force
ستوان, افسر میانی
see also first lieutenant, flight lieutenant, second lieutenant, sub lieutenant
2
an officer just below the rank mentioned
ستوان
a lieutenant colonel
3
(in the US) a police officer of fairly high rank
ستوان, افسر پلیس
4
a person who helps somebody who is above them in rank or who performs their duties when that person is unable to
نایب, معاون, کمک‌فرمانده, جانشین فرمانده