Most times, Guitar/bass wankery is when a guitarist/bassist makes excessive use of soloing and techniques such as shrills, taps, slaps & pops, slides, bends, sweeps and the like to the point where its nothing but self satisfaction.
Since such self satisfaction is often said to come from showing off to people with the talents listed above, it has become widely known amongst guitarist/bassist as Wankery.
2. Adjective describing something that has pretentions of being really serious and important, but is really just a bunch of bullshit.
3. Abstract noun referring to the property of being totally fucking retarded.
"This place reeks of wankery."