field gun vs swivel

field gun

noun
  • An artillery piece, originally a smaller gun that could accompany a field army on the march and when in combat could be moved about the battlefield in response to changing circumstances. 

swivel

noun
  • A small piece of ordnance, turning on a point or swivel; called also swivel gun. 

  • A piece, such as a ring or hook, attached to another piece by a pin, in such a manner as to permit rotation about the pin as an axis. 

  • Strength of mind or character that enables one to overcome adversity; confidence; force of will. 

  • The act of swivelling. 

  • A rotating of the hips. 

  • A small, usually ball- or barrel-shaped device used in angling to connect sections of fishing lines, consisting of two rings linked via a thrust bearing pivot joint. 

verb
  • To swing or turn, as on a pin or pivot. 

How often have the words field gun and swivel occurred in a corpus of books? (source: Google Ngram Viewer )