Guthmund is a masculine OE name formed from the elements the elements guð (‘combat, battle, war’) and mund (‘protector, guardian’). The PASE database currently identifies 6 persons named Guthmund in sources other than Domesday Book: the names is recorded three times in the ninth century, and three times in the eleventh.
Godmund is a plausible, albeit rare, Old English name, and since the occurrences of Godmund(us) seem, on prosopographical grounds, to have been held by different people, we have chosen to treat this name separately. PASE identifies just one person named Godmund: Godmund 1, a thegn who witnessed a spurious west Saxon charter dated 854.
Spellings in Domesday Book: Gudmund(us), Gudmunt, Guthmund(us) and Gutmundus
Forms in modern scholarship:
von Feilitzen head forms: Guðmund
Phillimore edition: Godmund. Guthmund, Godmund, Guthmundr
Alecto edition: Guthmund, Gothmund and Godmund