What does Joan mean?
A medieval English feminine of John, from Old French Johanne, ultimately from Hebrew 'Yochanan' ('Yahweh is gracious'). Like Jane, it descends from John rather than from Hannah.
What does Jane mean?
The common English feminine of John, from Old French Jehanne, ultimately from Hebrew 'Yochanan' meaning 'Yahweh is gracious.' A John-root grace name, distinct from the Hannah-root names.