keyholder

key +‎ holder

keyholder (plural keyholders)

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

   Synonym: claviger

2. (cryptography) The individual or organisation with access to a cryptographic key.
3. A device or component for holding a key.
   • 1978, Official Gazette of the United States Patent and Trademark Office, page 32:

     A key duplicating machine comprising […] a keyholder attached to said shaft, said keyholder providing for holding a key blank and an existing key having notches thereon; […]

4. (BDSM) 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.