From Irish seamróg, from Old Irish semróc, diminutive of semar, semair (“clover”), from Proto-Celtic *semarā, *semaris (compare Gaulish uisumaris (“clover”)), possibly from Proto-Indo-European *semh₁r-, *smeh₁r-. Related to Old Norse smári (“clover”) and possibly Georgian სამყურა (samq̇ura, “clover”).