The term 'Fiber Used in Basketmaking' can be summarized by two crossword solutions: ISTLE (5 letters) and RAFFIA (6 letters). ISTLE is a type of fiber obtained from the leaves of the agave plant, which is native to Mexico and Central America. It is used for making baskets, mats, and other items. RAFFIA is a type of palm fiber that is found in tropical regions of Africa, Asia, and South America. It is also used for basketmaking, as well as for making hats, bags, and other items.