A Central American tree of the genus Castilloa (formerly Castilla), or the crude rubber obtained from it.

Any of several South American trees of the genus Hevea (family Euphorbiaceae) which yield latex from which natural rubber is made; esp. the para…

A kind of caoutchouc derived from Urceola elastica, a woody climbing plant of the family Apocynaceæ; also, the plant itself.

rubber obtained from the coagulated latex of the tree Hevea brasiliensis (family Euphorbiaceae), esp. in the Amazon region to which it is native.

A flat, typically round mass of cured rubber, this being a form in which it is used by manufacturers of rubber products.

In the names of plants occurring in Honduras or products obtained from them. a natural rubber obtained from the Panama rubber tree, Castilla elastica…

see quots.

Para rubber.

Any of several varieties of rubber produced in the Amazon basin and Central America, esp. from species of Castilloa. Also attributive.

In various technical applications. = thimble-rubber n. at compounds 2.