9 letters · 17 points in Scrabble
originUnknown, but was popularized (as Kowa-Bunga) by Chief Thunderthud on the American children's show Howdy Doody in the late 1940s or early 1950s, and became associated with American surfing culture. By the early 1980s, it was used as the catch-phrase of Cookie Monster on the American television show Sesame Street, and gained popularity with a broader audience after its use in the American cartoon…
Etymology from Wiktionary, CC BY-SA 3.0