Bring back old Portuguese coins by petition (7)
I believe the answer is:
reissue
'bring back' is the definition.
Although both the answer and definition are verbs in their base form, I cannot see how they can define each other.
'old portuguese coins by petition' is the wordplay.
'old portuguese coins' becomes 'reis' (I've seen this in another clue).
'by' is a charade indicator (letters next to each other).
'petition' becomes 'sue' (I've seen this in another clue).
'reis'+'sue'='REISSUE'
Can you help me to learn more?
(Other definitions for reissue that I've seen before include "Send out again" , "get book brought out again" , "Do 11 Down again" , "Republish" , "Bring out again" .)