Technician running riot in Greene (8)
I believe the answer is:
engineer
'technician' is the definition.
(I've seen this before)
'riot in greene' is the wordplay.
'riot' indicates an anagram.
'in'+'greene'='ingreene'
'ingreene' is an anagram of 'ENGINEER'.
'running' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for engineer that I've seen before include "Machine designer, maker or operator" , "Plot" , "Practical technologist" , "Design and build" , "Designer of machines etc" .)