It’s pure branding nonsense. When the Wi-Fi Alliance was just getting started (and obviously before they were called the Wi-Fi Alliance) they hired a brand consulting firm to help come up with a catchy name. Wi-Fi, a play on the term hi-fi, was selected, and “The Standard for Wireless Fidelity” was selected as an advertising slogan. In essence, the term Wi-Fi is basically meaningless and was selected to coopt the sense of premium engineered-product quality implied by the term high fidelity.