natural rubber(n = noun.substance) caoutchouc, gum elastic, india rubber, rubber - an elastic material 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;

N  elasticity, springiness, spring, resilience, renitency, buoyancy, rubber, India rubber, Indian rubber, latex, caoutchouc, whalebone, gum elastic, baleen, natural rubber, neoprene, synthetic rubber, Buna- S, plastic, flexibility, Young's modulus, elastic, flexible, tensile, spring, resilient, renitent, buoyant, ductile, stretchable, extendable, the stress is proportional to the strain.