English of uncertain origin, possibly invented by Lord Brooke circa 1600 or by Fulke Greville around 1700.  It might be a rearrangement of the letters of Mary or from Latin "myrrh" or Latin "wonder".

Myra is used as an Anglicized form of Mairead the Scottish Highland variant of Margaret. Marietta is also an Anglicized form of Mairead so Myra and Marietta are consequently classified here as Lesser Synonyms.