Meaning of ensign

en•sign

1. a flag or banner, as a military or naval standard used to indicate nationality.
2. a badge of office or authority, as heraldic arms.
3. a sign, token, or emblem: the dove, an ensign of peace.
4. the lowest commissioned officer, ranking next below a lieutenant, junior grade, and equal to a second lieutenant in the Army.
5. standard-bearer (def. 1).