Answer Description

An Evil Twin is a wireless access point that is designed to mimic another Access Point's (AP) configuration in order to trick users into connecting to the incorrect network.

Wikipedia

An evil twin is a fraudulent Wi-Fi access point that appears to be legitimate but is set up to eavesdrop on wireless communications. The evil twin is the wireless LAN equivalent of the phishing scam. This type of attack may be used to steal the passwords of unsuspecting users, either by monitoring their connections or by phishing, which involves setting up a fraudulent web site and luring people there.