Dicky wearing black tuxedo composed love letter (6-4)

I believe the answer is:

billet-doux

'love letter' is the definition.
(synonyms)

'dicky wearing black tuxedo composed' is the wordplay.
'dicky' becomes 'ill' (I've seen this before).
'wearing' is an insertion indicator.
'black' becomes 'b' (as in pencil classifications).
'composed' indicates an anagram.
'b'+'tuxedo'='btuxedo'
'btuxedo' is an anagram of 'betdoux'.
'ill' placed within 'betdoux' is 'BILLET-DOUX'.

(Another definition for billet-doux that I've seen is " Love letter".)

I've seen this clue in The Telegraph.

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