The word 'byname' is correct and usable in written English.
It is a compound word formed by combining 'by' and 'name', and is used to mean an alternative or additional name, particularly when someone is known by a different name than their official or given name. Example: "John Smith is known by the byname 'Big John' among his friends due to his tall stature and commanding presence."
His byname, Martel, means "the hammer".
(Geoffrey's byname, Martel, means "the Hammer").
Eugene Andrew Cernan, byname Gene Cernan (born March 14 , 1934 Chicago, Illinois, U.S).
January 30 , 1911Pittsburgh, Pennsylvania February 26 , 1989Valley Stream, New York Roy Eldridge, in full David Roy Eldridge, byname Little Jazz (born January 30 , 1911 Pittsburgh, Pennsylvania, U.S. died February 26 , 1989 Valley Stream, New York) American trumpeter, one of the great creative musicians of the 1930s.
Martin Coles Harman, byname King Of Lundy (born 1885, Steyning, Sussex, Eng. died Dec. 5, 1954, Oxted, Surrey), English financier and one of the few private individuals particularly, one of the few persons while alive to have his portrait on coins.
September 9, 1890 Henryville, Indiana December 16, 1980 Shelbyville, Kentucky Harland Sanders, byname Colonel Sanders (born Sept. 9, 1890, near Henryville, Ind., U.S. died Dec. 16, 1980, Shelbyville, Ky).
1022 Sweden Olaf, byname Olaf the Tax King, Old Swedish Olof Skötkonung (died 1022, Sweden), king of Sweden (c. 980 1022) whose apparent efforts to impose Christianity were frustrated by the leading non-Christian Swedish chieftains.
1568 Brussels, Belgium January 13 , 1625Antwerp, Belgium Jan Bruegel the Elder, byname Velvet Bruegel, Dutch Jan Bruegel de Oude or Fluwelen Bruegel, Bruegel also spelled Brueghel or Breughel (born 1568, Brussels [now in Belgium] died January 13 , 1625 Antwerp), Flemish painter known for his still lifes of flowers and for his landscapes.
May 27, 1837 Troy Grove, Illinois August 2, 1876 Deadwood, South Dakota Wild Bill Hickok, byname of James Butler Hickok (born May 27 , 1837 Homer [now Troy Grove], Illinois, U.S. died August 2, 1876, Deadwood, Dakota Territory [now in South Dakota, U.S.]) American frontiersman, army scout, and lawman who helped bring order to the frontier West.
October 26, 1912 Chicago, Illinois April 20 , 1991Nipomo, California Don Siegel, byname of Donald Siegel (born October 26, 1912, Chicago, Illinois, U.S. died April 20 , 1991 Nipomo, California) American motion-picture director who specialized in action-packed films with tightly constructed narratives.
April 27, 1896 Winters, Texas January 5 , 1963Chicago, Illinois Rogers Hornsby, byname the Rajah (born April 27, 1896, Winters, Texas, U.S. died January 5 , 1963 Chicago, Illinois) American professional baseball player, generally considered the game's greatest right-handed hitter.
