Lacy, John an English mystical writer, flourished in the beginning of the 18th century. He joined the French prophets upon their appearance in London, and professed to have supernatural revelations. His principal works are, Warnings of the Eternal Spirit by the Mouth of his Servant John, surnamed Lacy (London, 1707, sm. 8vo):-A Relation of the Dealings of God to his unworthy Servant since the Time of his believing and professing himself inspired (London, 1708, small 8vo). He is also supposed to be the author of The general Delusion of Christians touching the Ways of God revealing himself to and by the Prophets (1713, 8vo); reprinted a few years since. See Darling, Encyclop. Bibliogr. vol. ii, s.v.