Wi-Fi doesn't actually stand for anything.

Despite the popular belief that Wi-Fi is short for “Wireless Fidelity,” the name was actually created in 1999 by a branding consultancy hired by the Wi-Fi Alliance, the industry group behind the wireless networking standard. It was chosen simply as a catchy, easy-to-say name, playing off the familiar term “hi-fi.”

The Wi-Fi Alliance did briefly use the tagline “The Standard for Wireless Fidelity” in some early marketing, which helped cement the mistaken belief that it was a genuine acronym. The underlying technical standard the name refers to is actually called IEEE 802.11.