Many in Foreign Office on retiring accepting outcome (2,3,2)
I believe the answer is:
no end of
'many' is the definition.
(I've seen this before)
'foreign office on retiring accepting outcome' is the wordplay.
'foreign office' becomes 'FO' (abbreviation).
'retiring' says the letters should be written in reverse.
'accepting' means one lot of letters goes inside another (inserted letters are accepted).
'outcome' becomes 'end' (I've seen this in another clue).
'fo'+'on'='foon'
'foon' reversed gives 'noof'.
'noof' going around 'end' is 'NO END OF'.
'in' is the link.
(Another definition for no end of that I've seen is " Many".)