ominous

Menacing; threatening.

Of or being an omen, especially an evil one.

Conveying some omen; serving as a sign or token; significant.

Of good omen; auspicious.

Of ill omen; giving indication of coming ill; portentous; inauspicious; unlucky.

Of or pertaining to an omen or to omens; being or exhibiting an omen; significant; portentous; — formerly used both in a favorable and unfavorable sense; now chiefly in the latter; foreboding or foreshowing evil; inauspicious.

Of or pertaining to an omen or to omens; being or exhibiting an omen; significant.

Specifically, giving indication of a coming ill; being an evil omen; threatening; portentous; inauspicious.

presaging ill fortune

threatening or foreshadowing evil or tragic developments