Supportive plays Neddy put on Irish stage totally slated initially (7)
I believe the answer is:
assists
'supportive plays' is the definition.
'assists' can be an answer for 'plays' (assist is a kind of play). I'm not sure about the 'supportive' bit.
'neddy put on irish stage totally slated initially' is the wordplay.
'neddy put' becomes 'ass' (I can't explain this - if you can you should believe this answer much more).
'on' means one lot of letters go next to another.
'initially' indicates taking the first letters.
The first letters of 'irish stage totally slated' is 'ists'.
'ass'+'ists'='ASSISTS'
Can you help me to learn more?
(Other definitions for assists that I've seen before include "Lends a hand" , "Contributes to success" , "Helps or waits on" , "Aids" , "Provides" .)