Viscoelastic

Part of speech: adjective

Definitions

1. A type of material that possesses characteristics of both viscosity, meaning resistance to flow, and elasticity, allowing it to revert to its original form after deformation under stress
2. Refers to substances that exhibit simultaneous viscous damping and elastic recovery, which make them respond to forces while exhibiting time-dependent behavior
3. A category of materials that combine the features of viscous flow resistance and elastic deformation, enabling them to absorb energy and return to their initial shape after stress

Etymology: Viscoelastic is a hybrid built from two older terms: "visco-", a combining form from "viscous" (from Latin "viscosus", "sticky", from "viscum", birdlime), and "elastic." The second half has a longer road. It traces back through Ancient Greek "elastos", meaning "driven" or "propelled," which passed through New Latin "elasticus" and French "élastique" before entering English as "elastic." The sense of springing back came later than the sense of being driven, a shift that suits a word now describing materials that both spring back and flow. The combination itself is a plain technical coinage, formed in the modern scientific period by joining the two words. Its meaning stays close to its parts: a material that resists a force partly like a viscous fluid, which dissipates energy as it flows, and partly like a spring, which stores and returns it. Honey poured slowly and a rubber band snapping back are both examples, and a material such as silly putty shows both behaviours at once.