Spanish Main

WordReference Random House Unabridged Dictionary of American English © 2026

Span′ish Main′, 

1. Place Names (formerly) the mainland of America adjacent to the Caribbean Sea, esp. the area between the mouth of the Orinoco River and the Isthmus of Panama.
2. Place Names the Caribbean Sea: the route of the Spanish treasure galleons and a former haunt of pirates.

Collins Concise English Dictionary © HarperCollins Publishers::

Spanish Main noun

1. the mainland of Spanish America, esp the N coast of South America from the Isthmus of Panama to the mouth of the Orinoco River, Venezuela
2. the Caribbean Sea, the S part of which in colonial times was the route of Spanish treasure galleons and the haunt of pirates