Defined unit, I suspect, not recognised (12)

I believe the answer is:

unidentified

'not recognised' is the definition.
(something unidentified has not been recognised)

'defined unit i suspect' is the wordplay.
'suspect' indicates an anagram (a suspicious or unusual spelling).
'defined'+'unit'+'i'='defineduniti'
'defineduniti' is an anagram of 'UNIDENTIFIED'.

(Another definition for unidentified that I've seen is " Not recognised".)

I've seen this clue in The Times.

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