Commoner from Temple Bar (4)
I believe the answer is:
pleb
'commoner' is the definition.
(I know that pleb is a type of commoner)
'from temple bar' is the wordplay.
'from' says the answer is hidden in the clue.
'PLEB' is hidden within 'temple bar'.
(Other definitions for pleb that I've seen before include "Boor" , "Commoner" , "Uncultivated type" , "Common guy" , "Person of vulgar tastes (colloq.)" .)