verb: (intransitive, Internet, informal) To participate in Internet Relay Chat.
noun: (Internet) Initialism of Internet Relay Chat. [(Internet) A protocol for instant communication via the Internet. Users connect to a network and join channels (chat rooms) where they can converse in typed text with other participants.]
noun: (US law) Initialism of Internal Revenue Code. [(finance, US) The domestic portion of federal statutory tax law in the United States.]
noun: Initialism of International Rescue Committee.
noun: (postal) Initialism of international reply coupon. [A prepaid international postage voucher.]