Stands for peers, stern, jumped-up (10)
I believe the answer is:
represents
'stands for' is the definition.
(representing is a kind of standing for)
'peers stern jumped-up' is the wordplay.
'jumped-up' indicates anagramming the letters.
'peers'+'stern'='peersstern'
'peersstern' is an anagram of 'REPRESENTS'.
(Other definitions for represents that I've seen before include "Stands for" , "plays" , "shows" , "Portrays" .)