Disguise noun, mysteriously, lacking candour (12)

I believe the answer is:

disingenuous

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'disguise noun mysteriously lacking candour' is the definition.
I can't tell whether this defines the answer.

'disguise noun mysteriously' is the wordplay.
'mysteriously' is an anagram indicator.
'disguise'+'noun'='disguisenoun'
'disguisenoun' with letters rearranged gives 'DISINGENUOUS'.

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(Other definitions for disingenuous that I've seen before include "Not sincere" , "Insincere" .)

I've seen this clue in The Irish Times.

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