jovinianist

from The Century Dictionary.

• noun Eccles., one of a short-lived sect, adherents of Jovinian, a Milanese monk of the fourth century, who at Rome opposed the prevalent esteem for celibacy, monasticism, fasting, and martyrdom, and maintained the equality of all sins, rewards, and punishments. He was excommunicated about 390, and went to Milan.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Script. Hist.) An adherent to the doctrines of Jovinian, a monk of the fourth century, who denied the virginity of Mary, and opposed the asceticism of his time.