Acetic
Acetic is a tasting term implying the presence of acetic acid. The term is used in reference to a vinegary smell present in many beverages, whether intentional or indicative of flaw. If it is in fact a flaw, the usual suspects are related to poor packaging or storage such as unclean draft lines. The flaw can also derive from production related issues such as a bacterial infection, introduction of oxygen during the "hot side" of brewing, or introduction of oxygen after fermentation.