It is a male name of the Swedish Gustav. It is assumed to be a variant of Augustus, although there are many more theories far from Latin, where Gustaf in Old Swedish would have the ending of stafr as "staff, staff of command, leadership and protection", but there is no agreement on the first component which could be göt ("ghats, people of southern Sweden"), or perhaps gutar ("Goths"), goð 333; s ("gods"), gund ("battle"), or the High German geist ("spirit"); The latter is also interpreted as "guest" and is shared by the Slavic gost, although in that language there is the word slav ("glory, honor") which as a suffix would give it the meaning of "honorable guest".
