an island of Hawaii to the northwest of Oahu
"Kauai is a lush and mountainous Hawaiian island located northwest of Oahu."
The oldest and fourth-largest island of Hawaii.
"During our road trip across Kauai, we visited waterfalls on the ancient volcanic landmass that is recognized as the oldest and fourth-largest island in Hawaii."
The name Kauai comes from the Hawaiian language, though its original meaning remains unknown to scholars. It was adopted into English as one of the principal islands of Hawaii.