threat vs umbrella

threat

verb
  • To press; urge; compel. 

  • To use threats; act or speak menacingly; threaten. 

noun
  • A person or object that is regarded as a danger; a menace. 

  • An indication of potential or imminent danger. 

  • An expression of intent to injure or punish another. 

umbrella

noun
  • Something that covers a wide range of concepts, purposes, groups, etc. 

  • The main body of a jellyfish, excluding the tentacles. 

  • A cloth-covered frame used for protection against rain or sun. 

  • Generally, anything that provides protection. 

  • An umbrella-shaped reflector with a white or silvery inner surface, used to diffuse a nearby light. 

verb
  • To move like a jellyfish. 

  • To cover or protect, as if by an umbrella. 

  • To form the dome shape of an open umbrella. 

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