Nonconformists, in English history, those who declined to conform their worship to that by law established. They were of two kinds: First, those who, being religious, worshiped nowhere; second, those who attended the services of some other religious denomination than the Established Church. It was more frequently used of the latter class. The name was first applied to those who declined to conform to the enactment of the Act of Uniformity of Edward VI., passed in 1549. It was revived and applied to the 2,000 clergymen, who had to surrender their livings on account of their inability to conform to the more celebrated Act of Uniformity of Charles II., first enforced on Aug. 24, 1662. Etymologically viewed, a Dissenter and Nonconformist somewhat differ. The former word denotes that he feels differently from Churchmen, that his sympathies go in a different direction; the latter word refers, not to his feelings, but to his action with respect to public worship. The laws formerly existing required him to conform to that of the Established Church by attending the services and partaking of the Communion. The two words, dissenter and non-conformist, as generally referring to the same individual, became interchangeable.
Entry from Everybody's Cyclopedia, 1912.