Definition

Corky is a disease symptom applied to roots whose surface resembles the texture of cork.

Above: A corky root of coffee (Coffea arabica), infected with root-knot nematodes (Meloidigyne konaensis).

Etymology. 1303, from Sp. alcorque "cork sole," prob. from Ar. al-qurq, ult. from L. quercus "oak" or cortex (gen. corticis) "bark." The verb "to stop with a cork" is from 1650; hence slang corker "something that closes a discussion" (1837). Corkscrew is from 1720; the verb is from 1837.