i Register
In some senses, scary is marked as informal, US, colloquial. Watch for register when choosing this word.
adj
Causing fear or anxiety
The tiger's jaws were scary.
She was hiding behind her pillow during the scary parts of the film.
Uncannily striking or surprising.
Linda changed her hair, and it’s scary how much she looks like her mother.
Subject to sudden alarm; easily frightened.
“Whist! whist!” said Natty, in a low voice, on hearing a slight sound made by Elizabeth, in bending over the side of the canoe, in eager curiosity; “’tis a sceary animal, and it’s a far stroke for a spear. […]”
“She’s cursed,” said the skipper; “speak her fair: I’m scary always to see her shake Her wicked head, with its wild gray hair, And nose like a hawk, and eyes like a snake.”
adv
To a scary extent; scarily.
At 199 centimetres and a hundred kilos going up, he was scary big and he found work as a bouncer and enforcer[.]
[T]he main reason I don't want to give her a GA is she's so scary fat!
noun
Barren land having only a thin coat of grass.