An old malicious heartless oddball (9)

I believe the answer is:

anomalous

'oddball' is the definition.
(thesaurus)

'an old malicious heartless' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'heartless' suggests removing the centre.
'malicious' with its centre taken out is 'malous'.
'an'+'o'+'malous'='ANOMALOUS'

(Other definitions for anomalous that I've seen before include "Atypical, exceptional" , "Inconsistent - out of place" , "Peculiar" , "Deviating from normal" , "Inconsistent, deviating from the norm" .)

I've seen this clue in The Times.

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