cold wallet

A cryptocurrency wallet that cannot be compromised because it is not connected to the Internet. Also called a "hardware wallet" and "offline wallet," the cold wallet stores the user's address and private key and works in conjunction with compatible software in the computer. Contrast with "hot wallet," which resides in the user's desktop or mobile device or in a cloud-based service, all of which are online to the Internet and can be hacked. See Bitcoin wallet.

Trezor Wallet - Only Hot for a Few Minutes

This cryptocurrency hardware wallet is only "hot" while it is plugged into the computer to make a transaction. When unplugged, it is "cold" and safe from eavesdropping. (Image courtesy of SatoshiLabs, www.trezor.io)