ass of Jack 

another, nicer way of calling someone a jackass

My ex is a complete ass of Jack.

ass of Jack by crowgrl13 October 1, 2008

jack ass of all trades 

a person who thinks he knows it all and is not swayed by the facts.

Regardless of the truth, Larry is a jack ass of all trades.

jack ass of all trades by Larry Johnson January 4, 2009