Definition - What does Rogue Access Point (Rogue AP) mean?
A rogue access point (rogue AP) is any wireless access point that has been installed on a network's wired infrastructure without the consent of the network's administrator or owner, thereby providing unauthorized wireless access to the network's wired infrastructure. Most of the time, rogue APs are set up by employees who want wireless access when none is available.
Techopedia explains Rogue Access Point (Rogue AP)
Another, and perhaps more common, example of a rogue access point is what is sometimes referred to as an "evil twin." This, at no time, involves unauthorized Ethernet connections as in the example above. Rather, this involves a wireless device just outside of an organization that receives beacons transmitted by legitimate access points within the organization. The evil twin then begins to transmit identical beacons with the intent of having end users within the organization connect with it. Once connected, the evil twin can then be used by nefarious individuals as an avenue into the organization's network.