WiFi stands for nothing

WiFi doesn’t really stand for Wireless Fidelity. It’s just a name. Like Nike, Reebok, Prozac. It was created by Interbrand, who is a leader in creating the creative names. The pun of wireless fidelity came from audio’s HiFi, which stood for High Fidelity.
Phil Belanger, a founding member of the Wi-Fi Alliance:

The only reason that you hear anything about “Wireless Fidelity” is some of my colleagues in the group were afraid. They didn’t understand branding or marketing. They could not imagine using the name “Wi-Fi” without having some sort of literal explanation. So we compromised and agreed to include the tag line “The Standard for Wireless Fidelity” along with the name. This was a mistake and only served to confuse people and dilute the brand. For the first year or so( circa 2000) , this would appear in all of our communications. I still have a hat and a couple of golf shirts with the tag line. Later, when Wi-Fi was becoming more successful and we got some marketing and business people from larger companies on the board, the alliance dropped the tag-line.

In case you didn’t know.
Via BoingBoing