1. Small, knobby tubers native to South America and used widely in the cookery of the Inca and Mayan civilizations. Ocas may be white, pink or red and have a firm potatolike flesh that can range in flavor from intensely sweet to slightly acidic. Choose firm, unblemished specimens; store in a cool, dark place for up to 1 month. Cook ocas in any manner suitable for potatoes. Also called New Zealand yam and papa roja. 2. Italian for "goose."