the GNU version of the Collaborative International Dictionary of English
n. An inferior or second lieutenant; in the British service, a commissioned officer of the lowest rank.
The Century Dictionary and Cyclopedia
n. In the British navy, a grade immediately below that of lieutenant. Formerly called mate.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. an officer ranking next below a lieutenant
Word Usage
"Ensign was the lowest rank in the US Army until 1800; the naval rank of ensign wasn't used until 1862, and of course the British equivalent is still sublieutenant."