- 1936: 9 baby girls named Moonyeen
- 1934: 5 baby girls named Moonyean [debut]
- 1933: 14 baby girls named Moonyeen
- 1922: 7 baby girls named Moonyeen [debut]
Where did the names come from, and why were they on the radar during those decades?
Looks like they can be traced back to the Broadway play Smilin’ Through (1919), which featured a character named Moonyeen. The story was popularized by several film adaptations, including Smilin’ Through (1922), starring Norma Talmadge, and Smilin’ Through (1932), starring Norma Shearer. (That 1932 version was nominated for the Academy Award for Best Picture, but lost to Cavalcade.)
I’m not entirely sure how the writers of the original Smilin’ Through came up with the name. My guess is that they based it on the Irish word muirnín, which means “darling” or “sweetheart.” It’s a term of endearment very similar to mo mhúirnín, “my darling,” which gave rise to the name Mavourneen.