Either from π³πΏ- (du-) + *π²πΉπ½π½π°π½ (*ginnan) (a Gothic formation) or inherited from Proto-Germanic *duginnanΔ . There are no other Germanic cognates with the same prefix which could be used to support the Proto-Germanic verb of the second etymology, but the unprefixed verb of the first etymology (*ginnanΔ ) is not attested in any Germanic language (which all except Gothic have descendants of the prefixed form *biginnanΔ , having the same meaning as this verb).
The element π³πΏ (du) is not attested in any other Germanic languages, probably being an archaic inheritance from Proto-Germanic that was lost early on in other Germanic languages. The archaic nature of the prefix might seem to point to a Proto-Germanic inheritance for this verb, but its clear productivity in Gothic renders this pointer uncertain.
π³πΏπ²πΉπ½π½π°π½ β’ (duginnan)
A variant spelling π³πΏπ²πΉπ½π½πΉπ³ (duginnid) is attested for expected (and unattested) π³πΏπ²πΉπ½π½πΉπΈ (duginniΓΎ).