Jewish and English from Hebrew "favoured one" or "God has been gracious"; OT 1 Samuel 1:2.
In the 1841 Census of Aberdeenshire the spelling Hanna was as frequent as Hanah, both being less than a quarter of the occurrences of Hannah. It is likely that some of these, particularly Hanna, were diminutives of Johanna [q.v.].
FreeREG gives Hannoria, with the appropriate case endings, as the Latin name used for Hannah in old documents; Hannor is also cited but without indicating how it's ending should be declined. A correspondent [JF2] reports that a further modification of the name to Honora occurs in some Irish records.
FreeREG also gives Hanna/Hannah and Ann/Anna as being Gaelic equivalents of Una.