Drinkipedia
Dumb
A wine that is dumb is one that is in a phase of muted aromas and flavors. It is a transitory phase that can happen in ageable wines in between fresh and fruity youth and expressive and developed maturity. During this period wine can taste dull and lifeless, yet it is expected to improve dramatically. (Wine,Beer,Spirits,Sake,Mead/Tasting Terms)