This is the 897th most frequent Slovenian word.
dobrega
"Dobrega" means "good" (genitive singular masculine/neuter or accusative singular masculine form).
In this sentence, 'dobrega' is in the genitive case, describing a singular, male noun (prijatelja) and indicating possession or association.
Poznaš kakšnega dobrega prijatelja?
Do you know any good friend?
Here, 'dobrega' is used in the accusative case to describe an undefined, singular neuter noun referring to 'something' (dobro) in Slovenian.
Želim nekaj dobrega za večerjo.
I want something good for dinner.
'Dobrega' here serves as an adjective in genitive case, modifying a singular, male noun (okusa) directly specifying the noun (vina).