Source : Webster's Revised Unabridged Dictionary (1913)

Rapid-fire \Rap"id-fire`\, Rapid-firing \Rap"id-fir`ing\, a.
   (a) (Gun.) Firing shots in rapid succession.
   (b) (Ordnance) Capable of being fired rapidly; -- applied to
       single-barreled guns of greater caliber than small arms,
       mounted so as to be quickly trained and elevated, with a
       quick-acting breech mechanism operated by a single motion
       of a crank or lever (abbr. R. F.); specif.: (1) In the
       United States navy, designating such a gun using fixed
       ammunition or metallic cartridge cases; -- distinguished
       from breech-loading (abbr. B. L.), applied to all guns
       loading with the charge in bags, and formerly from
       quick-fire. Rapid-fire guns in the navy also sometimes
       include automatic or semiautomatic rapid-fire guns; the
       former being automatic guns of not less than one inch
       caliber, firing a shell of not less than one pound
       weight, the explosion of each cartridge operating the
       mechanism for ejecting the empty shell, loading, and
       firing the next shot, the latter being guns that require
       one operation of the hand at each discharge, to load the
       gun. (2) In the United States army, designating such a
       gun, whether using fixed or separate ammunition, designed
       chiefly for use in coast batteries against torpedo
       vessels and the lightly armored batteries or other war
       vessels and for the protection of defensive mine fields;
       -- not distinguished from quick-fire. (3) In Great
       Britain and Europe used, rarely, as synonymous with
       quick-fire.