pearl harbor

noun

1. a harbor near Honolulu, on S Oahu, in Hawaii: surprise attack by Japan on the U.S. naval base and other military installations December 7, 1941.
2. any significant or crippling defeat, betrayal, loss, etc., that comes unexpectedly.

noun

1. an almost landlocked inlet of the Pacific on the S coast of the island of Oahu, Hawaii: site of a US naval base attacked by the Japanese in 1941, resulting in the US entry into World War II

A major United States naval base in Hawaii that was attacked without warning by the Japanese air force on December 7, 1941, with great loss of American lives and ships. In asking Congress to declare war on Japan the next day, President Franklin D. Roosevelt described the day of the attack as “a date which will live in infamy.”