The name Ceil is a girl's name of English origin meaning "blind". Ceil and is often added to lists like One-Syllable Middle Names for Girls and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
With the growing popularity of Celia and Cecilia, this vintage canasta-playing nickname name could be due for a comeback.
Ceil had a few years of recorded popularity in the first decade of the twentieth century, peaking in 1905.
One prominent bearer was fashion designer Ceil Chapman (born Cecilia),who was a favorite of actresses from the forties to the sixties--she was one of Marilyn Monroe's favorite designers. She also provided the trousseau for young Elizabeth Taylor's first wedding.
Caveat: Might be misheard as Seal.