The name Ismay is a girl's name of French origin meaning "esteemed, beloved". Ismay and is often added to lists like Unique Baby Names: Unusual and Rare and discussed in our forums with posts like "For Zelda's sister - your opinion on our shortlist?".
From the experts:
The rise of the the various Isabel names may give a boost to this variation, which has a sunny, springtime feel.
Although this name has been around since the thirteenth century, its origins remain obscure.
Ismay has appealed to several authors as a character name--Robertson Davies in his Cornish Trilogy, Ruth Rendell in The Water's Lovely, and Ken Follett in his World Without End.
Caveat: Could be confused with Esme.