Kahuna

Originally, Kahuna was the Hawaiian title for a shaman, and the term is still used in that context by some native Hawaiians.

In beach movies of the 1960s (et seq.) such as Beach Blanket Bingo, the "Big Kahuna" was the best surfer on the beach. This term later made its way from Hollywood into general surfing culture. (See also "The Big Kahuna".)

In some computer programming shops (for example, IBM), "Kahuna" is a synonym for "wizard" or "guru" (see internet slang).