Diph-thē'rī-ā, n.

n. [Gr. διφθέρα, a membrane.] (Med.) An epidemic disease in which the air passages, and especially the throat, become coated with a false membrane, produced by the solidification of an inflammatory exudation. It is accompanied with great prostration of strength: recovery is usually slow, and retarded by complications, as paralyses, &c.