| 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. |
| Pearl Harbor An inlet of the Pacific Ocean on the southern coast of Oahu, Hawaii, west of Honolulu. It became the site of a naval base after the United States annexed Hawaii in 1900. On Sunday, December 7, 1941, Japanese planes attacked the base, and the United States entered World War II the following day. |