What does caoutchouc mean?
Caoutchouc is the raw, elastic substance more familiarly known as natural rubber. It is obtained as a milky fluid called latex from tropical trees—most importantly the rubber tree, Hevea brasiliensis—and coagulates into a tough, flexible, water-resistant solid. Indigenous peoples of South America used it long before Europeans encountered it, fashioning it into balls, waterproof coatings, and containers. The word entered European languages through French and Spanish adaptations of an indigenous South American term, and it was the standard name for the material in the eighteenth and nineteenth centuries, when scientists such as Charles Goodyear worked to overcome its drawbacks of stickiness in heat and brittleness in cold. Today caoutchouc is largely a technical or historical term, used in chemistry and industry where precision matters, while everyday speech simply says 'rubber.'
nounA substance obtained as a milky sap (latex) from tropical trees, chiefly the rubber tree, which coagulates into the tough, elastic solid known as natural rubber.
- Raw natural rubber: the elastic, water-resistant coagulated latex of tropical trees, especially Hevea brasiliensis, before vulcanization or processing.
"The museum displayed an early raincoat fashioned from waterproofed caoutchouc."
"Early experimenters struggled to keep caoutchouc from turning sticky in summer heat and brittle in winter cold."
"Goodyear's vulcanization process finally made caoutchouc stable enough for commercial use."
Rarely pluralized; the plural appears mainly when referring to different varieties or samples of the material.
"The laboratory catalogued several distinct caoutchoucs gathered from different regions of the Amazon basin."
Before anyone called it 'rubber,' Europeans called this bouncy Amazonian tree-sap 'caoutchouc' — a name borrowed straight from the people who first showed them how to make bouncing balls with it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of caoutchouc
Caoutchouc entered English in the late eighteenth century by way of French, which took it from Spanish 'caucho'; the ultimate source is a word used by indigenous peoples of South America for the elastic tree sap they collected and worked. The same borrowing produced related forms across European languages, such as German Kautschuk. The common English name 'India rubber' arose later, reflecting the material's early use in erasing pencil marks.
How caoutchouc is actually used
Caoutchouc is a formal, technical, and somewhat old-fashioned term; in everyday English 'rubber' or 'natural rubber' is almost always used instead. It survives mainly in historical, scientific, and industrial writing, particularly when distinguishing unvulcanized material from processed rubber. The plural 'caoutchoucs' is rare, appearing only when referring to types or samples of the material.
Easily confused with caoutchouc
A cachou is a small aromatic lozenge for sweetening the breath, whereas caoutchouc is the raw elastic material known as natural rubber.