{ Ep`i*dem"ic (?), Ep`i*dem"ic*al (?), } a. [L. epidemus, Gr. &?;, &?;, among the people, epidemic; &?; in + &?; people: cf. F. épidémique. Cf. Demagogue.] 1. (Med.) Common to, or affecting at the same time, a large number in a community; -- applied to a disease which, spreading widely, attacks many persons at the same time; as, an epidemic disease; an epidemic catarrh, fever, etc. See Endemic.

2. Spreading widely, or generally prevailing; affecting great numbers, as an epidemic does; as, epidemic rage; an epidemic evil.

It was the epidemical sin of the nation.