double-barrelled vs reciprocal

double-barrelled

adj
  • Twofold, having a double purpose or nature. 

  • Having two separate parts, often adjoined by a line (or sometimes a space), e.g. Wright-Phillips. 

  • Used other than figuratively or idiomatically: see double, barrelled. Having two barrels, as a gun. 

  • Forceful, powerful (like a double-barrelled shotgun). 

reciprocal

adj
  • Expressing mutual action, applied to pronouns and verbs; also in a broad sense: reflexive. 

  • Mutually interchangeable. 

  • Of a feeling, action or such: mutual, uniformly felt or done by each party towards the other or others; two-way. 

  • Done, given, felt, or owed in return 

  • Used to denote different kinds of mutual relation; often with reference to the substitution of reciprocals for given quantities. 

noun
  • A construction expressing mutual action. 

  • The number obtained by dividing 1 by another given number; the result of exchanging the numerator and the denominator of a fraction. 

How often have the words double-barrelled and reciprocal occurred in a corpus of books? (source: Google Ngram Viewer )