The etymology of "Cuba" is unproven — but four theories compete:
Cubanacán or cubao in Classic Taíno (Arawakan) — meaning debated:
Columbus recorded Cubanacán in 1492 journal — locals used it for the interior.
Columbus named it La Juana (for Prince Juan, heir to Ferdinand/Isabella). Later Fernandina (for Ferdinand). Neither stuck. Taíno Cuba persisted among sailors, colonists, maps.
Coabana / Cubanacán → shortened to Cuba. Neighbor Hispaniola = "Little Spain" (La Española). Cuba = "The Other One" / "The Fertile One" — contrast naming.
Portuguese coba / couba = "basket" / "cavity." Early Portuguese charts (Cantino 1502) show Cuba. Possible: Portuguese explorers (pre-Columbus?) named it for shape (concave coast?) or abundance ("basket of provisions"). No documentary proof.
Taíno k → Spanish c (hard). Cubanacán [kuβaˈnakan] → Cuba [ˈkuβa]. Regular sound change.
Scholars lean Taíno cubanacán → Spanish Cuba. But no Rosetta Stone. The name survived empires, revolutions, and 500+ years — outliving its namers.