In certain ways, a neat arrangement by legislators (6)
I believe the answer is:
senate
'in certain ways' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'a neat arrangement by legislators' is the wordplay.
'arrangement' is an anagram indicator.
'by' is a charade indicator (letters next to each other).
'legislators' becomes 'se' (I can't justify this - if you can you should give a lot more credence to this answer).
'neat' anagrammed gives 'nate'.
'nate' put after 'se' is 'SENATE'.
Can you help me to learn more?
(Other definitions for senate that I've seen before include "The upper house in parliament or oireachtas" , "Second house of the Oireachtas" , "State assembly" , "Governors here" , "Legislative body" .)