the ominous sound of Snape’s dungeon door creaking open
They had been talking in low voices, but as the heavy door swung closed behind Harry an ominous silence fell.
It was an odd, unsettled sort of day; one moment the carriage was full of sunlight and the next they were passing beneath ominously grey clouds.
’Its a figure of speech!’ said Nearly Headless Nick, now so annoyed his head was trembling ominously on his partially severed neck.
As Harry and Ron handed Stan eleven Sickles each, the bus set off again, swaying ominously.
As though to complete the ominous picture, Hagrid was carrying what looked like half a dead cow over his shoulder.
’Don’t be silly, of course there is,’ said Hermione, and Harry saw, with an ominous feeling, that her face was suddenly alight with the kind of fervour that SPEW usually inspired in her.
By six o’clock that evening, however, even the glow of having successfully asked out Cho Chang could not lighten the ominous feelings that intensified with every step Harry took towards Snape’s office.
The stew skidded the length of the table and came to a halt just before the end, leaving a long black burn on the wooden surface; the flagon of Butterbeer fell with a crash, spilling its contents everywhere; the bread knife slipped off the board and landed, point down and quivering ominously, exactly where Sirius’s right hand had been seconds before.
Dolores Umbridge was standing in the doorway wrapped in a green tweed cloak that greatly enhanced her resemblance to a giant toad, and was smiling in the horrible, sickly, ominous way that Harry had come to associate with imminent misery.
The trees to which the other ends of the ropes around Grawp’s wrists and ankles were attached creaked ominously.
Uncle Vernon swelled ominously.
It occurred to him that he had never managed to get this far into the Forest without meeting some kind of creature; their absence struck him as rather ominous.
Hermione had been dropped, too, and Harry hurried towards her as two thick tree trunks parted ominously and the monstrous form of Grawp the giant appeared in the gap.
Meanwhile, several of the dragons and a large purple bat that was smoking ominously took advantage of the open door at the end of the corridor to escape towards the second floor.
Harry felt sure there ought to be a security person there, sure their absence was an ominous sign, and his feeling of foreboding increased as they passed through the golden gates to the lifts.
’Well — now don’t get upset, Molly, but Augustus Pye had an idea… he’s the Trainee Healer, you know, lovely young chap and very interested in… um… complementary medicine… I mean, some of these old Muggle remedies… well, they’re called stitches, Molly, and they work very well on — on Muggle wounds —’ Mrs Weasley let out an ominous noise somewhere between a shriek and a snarl.
There are no more uses of "ominous" in the book.
Show samples from other sources
I’m beginning to hear ominous rumblings of discontent.
With the clouds looking so ominous, I’m afraid there will be a bad storm.