Hold up street ballad (6)
I believe the answer is:
waylay
'hold up' is the definition.
(to waylay someone is to hold them up or delay them)
'street ballad' is the wordplay.
'street' becomes 'way' (road way).
'ballad' becomes 'lay' (synonyms).
'way'+'lay'='WAYLAY'
(Other definitions for waylay that I've seen before include "Ambush - detain in talk" , "Intercept and attack" , "Intercept and detain" , "Stop or interrupt (someone)" , "Lie in wait for, maybe to rob" .)