dehydration vs dry spell

dehydration

noun
  • The condition in which water in the body drops below normal levels, usually caused by illness, sweating or by not drinking enough. 

  • The act or process of removing water from something. 

dry spell

noun
  • A drawn-out period where the weather has been dry, for an abnormally long time; shorter and not as severe as a drought. 

  • A period or time where there is little activity, productivity, low income etc. 

  • A period of time without sexual intercourse. 

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