Definition of caoutchouc in US English:



  • Unvulcanized natural rubber.

    • ‘After the action is thought to be complete the article acted upon is to be washed with water so as to remove the whole of the acid solution, and it will be found that the surface of the caoutchouc will resemble that of soft cloth.’
    • ‘By adding a concentrated acid, the conversion of isoprene into caoutchouc artificiel, or artificial rubber, was speeded up a lot.’
    • ‘From a chemical point of view rubber is a carbohydrate consisting of high molecular weight chains of 1,4-polyisoprene residues in cis-configuration (caoutchouc).’
    • ‘Caoutchouc, as it exudes from the trees, is a milk-like emulsion, wherein globules of caoutchouc proper are suspended in a gummy solution.’
    • ‘The inflation process is also well-illustrated, ‘The balloon is composed of silk, varnished with the liquid gum caoutchouc.’’


Late 18th century: from French, from obsolete Spanish cauchuc, from Quechua kauchuk.