SOURCE OF POI is a term used to describe the origin of a Point of Interest (POI). The two crossword solutions for this term are TARO and EDDO, both of which are four letters long. TARO is a root vegetable that is widely cultivated in tropical and subtropical regions, while EDDO is a type of tuberous root vegetable that is native to Africa and Asia. Both of these vegetables are commonly used as sources of POI.