In the NATO spelling alphabet, “Whiskey” is the code word for the letter W.
The alphabet is officially the International Radiotelephony Spelling Alphabet. It was developed for clear communication by radio and telephone, where similar-sounding letter names can be misheard. Each letter receives a distinctive spoken code word, so a message such as a flight number, registration, or serial code can be spelled unambiguously.
The modern alphabet was standardized internationally through the International Civil Aviation Organization in the 1950s and later became widely associated with NATO. Its W word is spelled “Whiskey” in the NATO/ICAO version, although “whisky” is also a legitimate spelling in other contexts, especially for Scotch whisky and in some maritime references.
Common mix-ups include older spelling alphabets that used “William” or “Washington” for W. Those were historical alternatives, not the modern NATO code word. Nearby examples include Victor for V, X-ray for X, and Yankee for Y.