Tilly ranks #525 with 236 entries, registered female. The name is the diminutive of Matilda, a Germanic-origin name meaning "battle-mighty" — though the diminutive completely strips the warrior register and replaces it with bouncy, homey warmth. Most owners reach Tilly without ever invoking the Matilda back-form.
The cozy-diminutive register
Tilly clusters with Millie, Molly, Dolly, and Lily in the soft-double-consonant female pet-naming cohort. Owners reaching for these names are usually selecting for warmth and call-friendliness over ceremonial weight. The pattern skews heavily British in cultural register, even on American pets.
Breed lean and sound fit
Two syllables (TIL-ee), front-stressed, with an open trailing -ee that carries across a yard. Tilly lands disproportionately on small, fluffy, friendly-coded breeds — Cavalier King Charles Spaniels, Cocker Spaniels, Cockapoos, fluffy mixes, and warm-toned cats. The name almost never lands on rugged breeds; the sound is too soft.
The Matilda counter-reading
A small cohort of owners reach Tilly through the Roald Dahl novel Matilda (1988) or the 1996 film, picking Tilly as a play-friendly diminutive of the heroine. The literary anchor is real but quieter than the generic cozy-diminutive register. The Tilly baby name page shows modest SSA presence climbing through the 2010s.
Owners reaching for Tilly often skip the Matilda back-form entirely, treating Tilly as the full given name from day one. The name on its own carries enough warmth to stand without the formal long-form anchoring it.