miscreant (n.)
late 14c., "heathen, Saracen," from miscreant (adj.) or from Old French mescreant, which also had a noun sense of "infidel, pagan, heretic." Sense of "villain" first recorded 1590 in Spenser.
miscreant (adj.)
c. 1300, "non-Christian, pagan, infidel;" early 15c., "heretical, unbelieving," from Old French mescreant "disbelieving" (Modern French mécréant), from mes- "wrongly" (see mis- (2)) + creant, present participle of creire "believe," from Latin credere "to believe" (see credo). Meaning "villainous" is from 1590s.