1550s, member of a Jewish sect (first recorded 2c. B.C.E.), from Latin, from Greek Essenoi, of disputed etymology, perhaps from Hebrew tzenum "the modest ones," or Hebrew hashaim "the silent ones." Klein suggests Syriac hasen, plural absolute state of hase "pious."
a Jewish mystical sect somewhat resembling the Pharisees. They affected great purity. They originated about B.C. 100, and disappeared from history after the destruction of Jerusalem. They are not directly mentioned in Scripture, although they may be referred to in Matt. 19:11, 12, Col. 2:8, 18, 23.