Calihan is an uncommon, unisex given name of Irish origin. It is derived from the Irish surname Calahan, which is believed to be an Anglicized form of the Gaelic Ó Ceallaigh, meaning "descendant of Ceallach." Ceallach is a personal name that means "bright-headed" or "hard-headed," with roots in the Old Irish word 'ceall' meaning "strife" or "battle." The name Calihan, while not as well-documented as some other names, has been occasionally used as a given name in Ireland and among the Irish diaspora. It is also sometimes found as a surname, though it is much rarer than the Calahan surname from which it originates.
"Calihan saw steady birth numbers from 2020 to 2021 with six babies each year, followed by five in 2022, bringing the total over these three years to seventeen."