Douglas Harper's Etymology Dictionary
Lubish
1610s, from German lübisch, Dutch lubeksch, from Lübeck, Hanseatic city in northern Germany, formerly a trade center, hence its use as an adjective in English. The city was founded 1143 and is said to be named for the former principality of the Liubichi, literally "the people of prince Liub" (literally "beloved").\n
Wiktionary
lubish
a. 1 (context monetary historical English) Relating to denominations belonging to a money of account formerly in extensive mercantile use in North Germany. 2 (context UK dialectal English) genuine; authorised; sterling. 3 A strong beer brewed at http://en.wikipedia.org/wiki/L%C3%BCbeck.