The Collaborative International Dictionary of English v.0.48:

Ill-omened \Ill`-o"mened\, a.
   Having unlucky omens; inauspicious. See Note under Ill,
   adv.

   Syn: ill-fated, ill-starred, unlucky.
        [1913 Webster]

WordNet (r) 3.0 (2006):

ill-omened
    adj 1: marked by or promising bad fortune; "their business
           venture was doomed from the start"; "an ill-fated
           business venture"; "an ill-starred romance"; "the unlucky
           prisoner was again put in irons"- W.H.Prescott [syn:
           doomed, ill-fated, ill-omened, ill-starred,
           unlucky]