/ ˈensən; NAmE / noun
1.
a flag flown on a ship to show which country it belongs to :
the White Ensign (= the flag of the British Navy)
2.
an officer of low rank in the US navy :
Ensign Marshall
••
WORD ORIGIN
late Middle English : from Old French enseigne , from Latin insignia signs of office, neuter of insignis distinguished (as if by a mark), from in- towards + signum sign.