Gilly is a name that sounds like a creature in a children's book — round, cheerful, slightly mischievous, and guaranteed to make people smile when they hear it. It functions as both a standalone name and as a nickname for Gillian, Gilda, or Gilberta, and for most pet owners it simply arrives pre-abbreviated and ready to use.
The Friendly -ee Sound
Names ending in the -ee sound dominate female pet naming because they carry warmth and approachability without effort. Gilly shares acoustic family with Millie, Lily, Rosie, and Tillie: a cohort of names that feel consistently gentle and affectionate. Cocker Spaniels and fluffy small breeds are natural homes for names in this register.
Game of Thrones Gilly
Gilly from Game of Thrones, the wildling woman who learns to read and raises her son with Samwell Tarly, is a specifically warm and resilient character in an otherwise brutal story. Pet owners who know the reference get a quietly optimistic layer beneath the cheerful sound. Unlike many character names from the show, Gilly carries no violent or tragic associations, which makes it an unusually safe Game of Thrones naming choice.
Counter-Reading: Very Informal Register
Gilly is a name that commits fully to warmth and informality. It offers no formal gear; there's no Gilly that commands a boardroom. For owners who want a pet name that can do both registers, a longer form like Gillian registered formally gives you the flexibility, with Gilly as the daily shorthand.