Arabian Sea, ancient Mare Erythraeum, northwest part of the Indian Ocean, lying between Arabia and India. The Gulf of Aden, extended by the Red Sea, and the Gulf of Oman, extended by the Persian Gulf, are its principal arms. The submarine Carlsberg ridge, SE of Socotra Island, is the sea's southern boundary. The Indus River is the largest stream flowing into the sea. The Arabian Sea has long been an important trade route between India and the West; its chief ports are Aden, Yemen; Karachi, Pakistan; and Mumbai, India.

Northwestern part of the Indian Ocean, lying between India and the Arabian Peninsula. It has an area of about 1,491,000 sq miles (3,862,000 sq km) and an average depth of 8,970 feet (2,734 m). The Gulf of Oman connects it with the Persian Gulf via the Strait of Hormuz, while the Gulf of Aden connects it with the Red Sea via the Strait of Mandeb. The Indus is the principal river draining into the Arabian Sea. Socotra, Lakshadweep, and other islands lie within it. Chief ports are Mumbai (Bombay), India; Karachi, Pak.; and Aden, Yemen. The sea has been part of the principal trade route between Europe and India for centuries.

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