Short and rude letter in the play at the very end (7)
I believe the answer is:
curtain
'end' is the definition.
(thesaurus)
'short and rude letter in' is the wordplay.
'short' becomes 'curt' (synonyms).
'and' is a charade indicator (letters next to each other).
'rude letter' becomes 'a' (I am not sure about the 'rude' bit.).
'curt'+'a'+'in'='CURTAIN'
'the play at the very' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for curtain that I've seen before include "See 1" , "Stage concealer" , "Cover for window etc" , "Final instruction of play" , "It's raised before the start of a play" .)