Clever Trousers 

Someone who makes snide remarks, or otherwise is acting in a fashion that makes others believe they are being smug.

British in origin.

Exactly the same as Smarty Pants.

"Oh, you're such a clever trousers with your puns, AREN'T you, Neil?"

Clever Trousers by Asura October 26, 2004

clever trousers 

A person who cannot let anything go by. They always have to answer back in a condesending way. These are usually people who are higher in the academic world than their peers and they use their knowledge in a mean way.

"He had to say that just to be a clever trousers. Who cares if pigs don't really sweat that much?"

clever trousers by mickey November 23, 2004