1. Add to a list of approved items or people
   "We whitelisted the company's email domain to ensure important messages weren't blocked"

1. A list of approved items or people, esp. e-mail addresses or web sites that are trusted or assumed to be virus and spam free
   "The IT department maintains a whitelist of safe websites for employees to access"

Derived forms: whitelisted, whitelisting, whitelists

Encyclopedia: Whitelist