This decade went into the ropes (8)
I believe the answer is:
twenties
'this decade' is the definition.
(eg the 1920s)
'went into the ropes' is the wordplay.
'into' means one lot of letters goes inside another.
'the ropes' becomes 'ties' (I can't explain this - if you can you should give a lot more credence to this answer).
'went' placed within 'ties' is 'TWENTIES'.
Can you help me to learn more?
(Other definitions for twenties that I've seen before include "ten years" , "what lies ahead for 27 [TEENAGER]?" , "decade of frivolity" , "They were roaring in the last century" , "The decade was said to be roaring" .)