Pench is someone quite stupid / retarded that like the trend, but then fails at setting a new one by using a word that rhymes with a 'sick' word and killing it -.-
Jamie - 'That t-shirt is pench'
Matt - 'Yeahh'
Luke & Chris 'Leave it yeahhhhhhhh'
The word "pench" Was Created by the great Mel Gibson. It refers to when someone "pinches". Can be used in many different ways in many different conversations.