The term OCA is an acronym for Oxalis tuberosa, a species of edible root vegetable native to the Andes Mountains in South America. The crossword solutions for OCA are 'TUBER' (5 letters) and 'edibleroot' (10 letters). TUBER refers to the underground stem of the plant which is edible and can be cooked or eaten raw. Edibleroot is a descriptive term for the edible root of the plant, which is also known as oca or yam.