keychain vs keyholder

keychain

noun
  • A chain or ring to which a key may be attached. 

  • An ornamental piece holding such a chain or ring. 

  • A digital repository for the storage of cryptographic keys. 

keyholder

noun
  • A device or component for holding a key. 

  • The individual or organisation with access to a cryptographic key. 

  • A dominant partner who controls whether their submissive partner is able or allowed to orgasm or receive sexual stimulation, typically by locking the submissive partner in a chastity belt or chastity cage. 

  • One who holds the key to a building etc. for security reasons. 

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