1. (noun)rubber, natural rubber, India rubber, gum elastic, caoutchouc an elasticmaterial obtained from the latex sap of trees (especially trees of the genera Hevea and Ficus) that can be vulcanized and finished into a variety of products
3. (noun)rubber eraser, rubber, pencil eraser an eraser made of rubber (or of a syntheticmaterial with properties similar to rubber); commonly mounted at one end of a pencil