The name Gail is a girl's name of Hebrew origin meaning "my father rejoices". Gail and is often added to lists like Midcentury Baby Names and discussed in our forums with posts like "ALPHABET Drop 2 Add 1 - Girls".
From the experts:
Gail was a mid-twentieth century favorite, which has been far surpassed by its original form, Abigail and nickname Abby. Spelling variations include Gale and Gayle, the latter represented by TV journalist and Oprah bestie Gayle King. Gail was most popular in the 1950s, when it was in the Top 40, and could rise again, possibly as a middle.