girth strap vs surcingle

girth strap

noun
  • A cinch or a girth: a strap round the belly of an animal used to hold a saddle in place. 

surcingle

noun
  • A piece of tack wrapped around the belly of a horse, to use when longeing. 

  • A girdle to fasten a garment, especially a cassock. 

  • A long unpadded strap to pass over and keep in place a blanket, pack or saddle on an animal. 

verb
  • To fasten with a surcingle. 

How often have the words girth strap and surcingle occurred in a corpus of books? (source: Google Ngram Viewer )