English and Polish form of Latin Iohanna, which was derived from Greek Ἰωάννα (Ioanna), the feminine form of Ioannes (see John). This is the spelling used in the English New Testament, where it belongs to a follower of Jesus who is regarded as a saint. In the Middle Ages in England it was used as a Latinized form of Joan (the usual feminine form of John) and it became common as a given name in the 19th century.