A distinguishing flag or banner; standard; badge; symbol.
A military or naval officer.
" I'm sure it's not my wish to be bad friends," said Ensign Long. – Middy and Ensign by G. Manville Fenn
" Mr. Brooks, the jailer, is here- Ensign Martin and Brincle, of the Georgia guard," was the reply of the jailer. – Guy Rivers: A Tale of Georgia by William Gilmore Simms