Ep`i*dem"ic (?), Ep`i*dem"ic*al (?), a. [L. epidemus, Gr. , , among the people, epidemic; in + people: cf. F. 'epid'emique. 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.
Bp. Burnet.
© Webster 1913.