Made up again by popular outlet with a fair amount of grass on either side (10)
I believe the answer is:
reinvented
'made up again' is the definition.
('invented' can be a synonym for 'made up' so perhaps 'reinvented' is OK for 'made up again')
'grass on either side' is the wordplay.
'grass' becomes 'reed' (I've seen this before).
'on' means one lot of letters goes inside another (as in clothing \'on\' a person).
'either side' becomes 'invent' (I can't justify this - if you can you should give a lot more credence to this answer).
'reed' enclosing 'invent' is 'REINVENTED'.
'by popular outlet with a fair amount of' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Another definition for reinvented that I've seen is " Thought up again".)