Either of two early Italian saints (who may have been the same person) traditionally commemorated on February 14—a Roman priest martyred c.269 and a bishop of Terni martyred at Rome. St. Valentine was regarded as the patron of lovers.
Definition of Valentine, St. in US English:
Valentine, St.
proper nounˈvalənˌtīn
Either of two early Italian saints (who may have been the same person) traditionally commemorated on February 14—a Roman priest martyred c.269 and a bishop of Terni martyred at Rome. St. Valentine was regarded as the patron of lovers.