Creation of Morse concerns Oxford detective Endeavour, primarily (4)

I believe the answer is:

code

'creation of morse' is the definition.
(as in Morse code)

'concerns oxford detective endeavour primarily' is the wordplay.
'primarily' suggests taking the first letters.
The initial letters of 'concerns oxford detective endeavour' is 'CODE'.

(Other definitions for code that I've seen before include "Kind of encryption designed to disguise content" , "Method of encryption or set of rules" , "Post -; dialling -" , "Cipher - set of principles" , "Secret system of letters. words etc" .)

I've seen this clue in The Times.

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