Record major returning congestion (3,3)
I believe the answer is:
log jam
'congestion' is the definition.
(log jam is a type of blockage)
'record major returning' is the wordplay.
'record' becomes 'log' (logging is a kind of recording).
'major' becomes 'maj' (I can't explain this - if you can you should give a lot more credence to this answer).
'returning' says the letters should be written in reverse.
'maj' back-to-front is 'jam'.
'log'+'jam'='LOG-JAM'
Can you help me to learn more?
(Other definitions for log jam that I've seen before include "Deadlock; river blockage" , "A deadlock or work accumulation" , "standstill" , "A deadlock of wooden proportions" , "hindrance to progress" .)