Hello Ms. Bardugo, what inspired you to think of the word Grisha? Did it have something to do with the word Geisha?

Yes! 

The Grisha: I chose the name Grisha for the magical elite because it is the Russian diminutive of Gregory which means “watchful” and derives from the biblical Grigori (which a lot of paranormal fans will recognize from fallen angel tales). It also evokes the word “geisha,” which reinforces the sense of beauty, secrecy, and the elite.

This is from a larger piece I wrote on language and naming, that you can find here.