That drunk uncle everybody has who always gets hammered at family events. Usually this individual will puke, cause a fight or both and is estimated to have a short life expectancy.
A drunk uncle. The classic situation when one of you parent's brothers drinks far too much at some sort of social event, thus resulting in them performing an embarrassing act. Hence they are a Drunkle.
An uncle to tends to drink too much, often becoming boisterous for no reason.
Less common, but still appriopriate: An uncle who tends to overindulge at family social events, often causing more turmoil than necessary, and acts like an ass. This "ass" behavior could manifest itself in numerous ways such as; hitting on younger girls near his own daughters age, bringing up inappropriate situations during toasts, arguing at great length over trivial matters, etc...
Man, Holly's fucking uncle is always drunk, he completely ruined her wedding, he's such a drunkle.