Inauspicious wrongdoing tires out (8)
I believe the answer is:
sinister
'inauspicious' is the definition.
(thesaurus)
'wrongdoing tires out' is the wordplay.
'wrongdoing' becomes 'sin' (sin is a kind of wrongdoing).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'tires' with letters rearranged gives 'ister'.
'sin'+'ister'='SINISTER'
(Other definitions for sinister that I've seen before include "Threatening - ominous" , "Suggestive of evil, being lefthanded" , "Threatening the left in heraldry" , "can be injurious" , "Suggestive of evil, threatening harm" .)