noun
westbound sea route; east-to-west sea route
Refers to a sea route that goes westward, often used in historical contexts such as the Spanish trade route from the Philippines to Mexico.
西回り航路は、マゼラン海峡を経由して太平洋を横断した。
The westbound sea route crossed the Pacific via the Strait of Magellan.
Eastbound sea route, the opposite direction.
Compound of 西 (west) + 回り (going around) + 航路 (sea route).