hydra vs pain

hydra

noun
  • A complex, multifarious problem or situation that cannot be solved easily and rapidly. 

  • Any of several small freshwater polyps of the genus Hydra and related genera, having a naked cylindrical body and an oral opening surrounded by tentacles. 

  • A dragon-like creature with many heads and the ability to regrow them when maimed. 

pain

noun
  • Labour; effort; great care or trouble taken in doing something. 

  • An ache or bodily suffering, or an instance of this; an unpleasant sensation, resulting from a derangement of functions, disease, or injury by violence; hurt. 

  • The condition or fact of suffering or anguish especially mental, as opposed to pleasure; torment; distress 

  • An annoying person or thing. 

verb
  • To feel pain; to hurt. 

  • To hurt; to put to bodily uneasiness or anguish; to afflict with uneasy sensations of any degree of intensity; to torment; to torture. 

  • To render uneasy in mind; to disquiet; to distress; to grieve. 

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