imp vs nymph

imp

noun
  • A mischievous child. 

  • A small, mischievous sprite or a malevolent supernatural creature, somewhat comparable to a demon but smaller and less powerful, formerly regarded as the child of the devil or a demon (see sense 3.2). 

  • A baby Tasmanian devil. 

verb
  • To add to or unite a object with (something) to lengthen the latter out or repair it; to eke out, enlarge, strengthen. 

  • To provide (someone or something) with wings, hence enabling them or it to soar. 

  • To engraft (a feather) on to a broken feather in a bird's wing or tail to repair it; to engraft (feathers) on to a bird, or a bird's wing or tail. 

nymph

noun
  • A young girl, especially one who is attractive, beautiful or graceful. 

  • The larva of certain insects. 

  • Any female nature spirit associated with water, forests, grotto, wind, etc. 

  • Any of various butterflies of the family Nymphalidae. 

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