Part of theatre finale that’s particularly welcome (7)
I believe the answer is:
godsend
'particularly welcome' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'part of theatre finale' is the wordplay.
'part of theatre' becomes 'gods' (I can't justify this - if you can you should believe this answer much more).
'finale' becomes 'end' (the end of a story or show).
'gods'+'end'='GODSEND'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for godsend that I've seen before include "Something very opportune" , "Welcome surprise" , "Very welcome thing" , "welcome acquisition" , "Dog's den (anag.)" .)