Cassidy is a gender-neutral given name derived from the Irish surname Ó Caiside, which in turn comes from the Gaelic byname Caiside. The name Caiside itself means "curly-haired," tracing back to the Irish word cas, meaning "twisted, curly." Anglicized from the original Gaelic, Cassidy thus carries the connotation of describing someone with curled or twisted hair, albeit metaphorically as a surname passed down through generations.Etymology and OriginsThe Gaelic root cas is a common element in Irish naming conventions, often used in physical descriptions. As an Anglo-Irish surname (Ó Caiside), it originally meant "descendant of Caiside," referring to a sept (clan) found primarily in County Fermanagh and surrounding areas. The name's transition to a given name began slowly in English-speaking regions, reflecting a broader trend of adopting surnames as first names.PopularityVery rare before the 1970s, Cassidy first appeared among the 1,000 most popular names for girls in the United States in 1981. Its popularity surged during the 1980s and peaked in 1999, when it ranked 99th for American girls. Usage also rose in Canada, the United Kingdom, and other English-speaking countries during the 1990s and early 2000s. For boys, Cassidy has charted in the US since 1983 and peaked at 665th in popularity in 1984, making it consistently more common for girls.Notable BearersA number of contemporary individuals bear the name Cassidy, contributing to its visibility. These include Cassidy Benintente (born 1994), an American soccer player; Cassidy Cox (born 1998), an American archer; Cassidy Davis (born 1994), an Australian footballer; and Cassidy Doneff (born 1986), an American field hockey player. The name also appears in pop culture, most notably Cassidy from the Preacher comics and Cassidy (also known as C.B.), a fictional daredevil in Kickin' It. Perhaps most famous is the animated marsupial Kassidy from T.U.F.F. Puppy, helping tie the name to fun, spirited characters.Related FormsVariants include Kassidy, a phonetic spelling that saw its peak for girls at 314th in popularity in 2000. Diminutives and short forms popular as nicknames include Cass, Cassie, and Cassy, the latter two often considered independent given names over time.Meaning: "Curly-haired" (from Gael. cas)Origin: Irish surname Ó CaisideType: First name from surnameUsage Regions: United States, Canada, UK, Australia, Ireland