cognomen meaning and definition

COGNOMEN noun

Definition of cognomen (noun)

1. a familiar name for a person (often a shortened version of a person's given name)
   • "Joe's mother would not use his nickname and always called him Joseph"; "Henry's nickname was Slim"
   • synonyms: byname, moniker, nickname, sobriquet, soubriquet
2. the name used to identify the members of a family (as distinguished from each member's given name)
   • synonyms: family name, last name, surname