From The Collaborative International Dictionary of English v.0.48:
Gunner \Gun"ner\, n.
1. One who works a gun or cannon, whether on land, sea, or in
the air; a cannoneer.
[1913 Webster]
2. A warrant officer in the navy having charge of the
ordnance on a vessel.
[1913 Webster]
3. (Zool.)
(a) The great northern diver or loon. See Loon.
(b) The sea bream. [Prov. Eng. or Irish]
[1913 Webster]
Gunner's daughter, the gun to which men or boys were lashed
for punishment. [Sailor's slang] --W. C. Russell.
tail gunner (Mil.) A member of the crew of a bomber
airplane who operates the defensive gun at the rear of the
airplane.
[1913 Webster +PJC]