Synonyms of the word

alarming

• v. present participle of alarm.
• adj. causing apprehension, fear or alarm; frightening.

appalling

• v. present participle of appall.
• adj. Horrifying and astonishing.

atrocious

• adj. Frightful, evil, cruel, or monstrous.
• adj. Offensive or heinous.
• adj. Very bad; abominable, disgusting.

awful

• adj. Oppressing with fear or horror; appalling, terrible.
• adj. (now rare) Inspiring awe; filling with profound reverence or respect; profoundly impressive.
• adj. Struck or filled with awe.
• adj. (obsolete) Terror-stricken.
• adj. Worshipful; reverential; law-abiding.
• adj. Exceedingly great; usually applied intensively.
• adj. Very bad.
• adv. (colloquial, US, Canada) Very, extremely.

baleful

• adj. Portending evil; ominous.
• adj. Miserable, wretched, distressed, suffering.

bloodcurdling

• adj. Causing great horror or terror.

chilling

• adj. Becoming cold.
• adj. Causing cold.
• adj. Causing mild fear.
• v. present participle of chill.
• n. The act by which something is chilled.

creepy

• adj. (informal) Producing an uneasy fearful sensation, as of things crawling over one's skin.
• adj. (informal) Strangely repulsive.

creepy-crawly

• n. Any small crawling animal such as a spider, insect or worm.
• n. (Australia, informal, trademark erosion) an automated suction pool cleaner.

dire

• adj. Warning of bad consequences: ill-boding; portentous.
• adj. Requiring action to prevent bad consequences: urgent, pressing.
• adj. Expressing bad consequences: dreadful; dismal; horrible; terrible; lamentable.
• adj. (informal) Bad in quality, awful, terrible.

direful

• adj. Fearful, terrible.

dismaying

• v. present participle of dismay.

dread

• v. (transitive) To fear greatly.
• v. To anticipate with fear.
• v. (intransitive) To be in dread, or great fear.
• v. (transitive) To style (the hair) into dreadlocks.
• n. Great fear in view of impending evil; fearful apprehension of danger; anticipatory terror.
• n. Reverential or respectful fear; awe.
• n. Somebody or something dreaded.
• n. (obsolete) A person highly revered.
• n. (obsolete) Fury; dreadfulness.
• n. A Rastafarian.
• n. (chiefly in the plural) dreadlock.
• adj. Terrible; greatly feared.
• adj. (archaic) Awe-inspiring; held in fearful awe.

dreaded

• adj. Causing fear, dread or terror.
• adj. Wearing dreadlocks.
• v. simple past tense and past participle of dread.

dreadful

• adj. (obsolete) Full of dread, whether.
• adj. Full of something causing dread, whether.
• n. A shocker: a report of a crime written in a provokingly lurid style.
• n. A journal or broadsheet printing such reports.
• n. A shocking or sensational crime.

fearful

• adj. Frightening.
• adj. (now rare) Frightened, filled with terror.
• adj. Tending to fear.
• adj. (dated) Terrible; shockingly bad.

fearsome

• adj. frightening, especially in appearance.
• adj. (rare or archaic) fearful, frightened.

forbidding

• adj. highly unpleasant or disagreeable.
• adj. threatening or menacing.
• v. present participle of forbid.
• n. The act by which something is forbidden; a prohibition.

formidable

• adj. Causing fear, dread, awe, or discouragement as a result of size, strength, or some other impressive feature;…
• adj. Difficult to defeat or overcome.

frightening

• adj. Causing fear; of capable of causing fear; scary.
• adj. (figuratively) Awful, terrible, very bad.
• v. present participle of frighten.

frightful

• adj. (obsolete) Full of fright, whether.
• adj. Full of something causing fright, whether.

ghastly

• adj. Like a ghost in appearance; death-like; pale; pallid; dismal.
• adj. Horrifyingly shocking.
• adj. Extremely bad.
• adv. In a ghastly manner.

grim

• adj. dismal and gloomy, cold and forbidding.
• adj. rigid and unrelenting.
• adj. ghastly or sinister.
• adj. (Britain, slang) disgusting; gross.

grisly

• adj. Horrifyingly repellent; gruesome, terrifying.
• adv. (obsolete) In a horrible or terrible manner; in a terrifying way.

gruesome

• adj. repellently frightful and shocking; horrific or ghastly.

hair-raising

• adj. Causing fear; scary.

hairy

• adj. Of a person, having a lot of hair on the body.
• adj. Of an animal, having a lot of fur.
• adj. Of a body part other than the head, having hair growing from it.
• adj. Difficult, complex, intricate, or intimidating.

horrendous

• adj. Extremely bad; awful; terrible.

horrible

• n. A thing that causes horror; a terrifying thing, particularly a prospective bad consequence asserted as…
• n. A person wearing a comic or grotesque costume in a parade of horribles.
• adj. Causing horror; terrible; shocking.
• adj. Tremendously bad.

horrific

• adj. Horrifying, causing horror; horrible.

horrifying

• v. present participle of horrify.
• adj. Tending to inspire horror; that horrifies; horrific.

macabre

• adj. Representing or personifying death.
• adj. Obsessed with death or the gruesome.
• adj. Ghastly, shocking, terrifying.

menacing

• adj. Suggesting imminent harm.
• adj. Threatening.
• v. present participle of menace.
• n. The act of making menaces or threats.

minacious

• adj. (now rare) Threatening, menacing.

minatory

• adj. Threatening, menacing.

nightmarish

• adj. Resembling a nightmare.

ominous

• adj. Of or pertaining to an omen or to omens; being or exhibiting an omen; significant.
• adj. Specifically, giving indication of a coming ill; being an evil omen; threatening; portentous; inauspicious.

petrifying

• adj. Causing immense fear; immobilising with fright; scary; frightening; terrifying.
• v. present participle of petrify.

redoubtable

• adj. Eliciting respect or fear; imposing; awe-inspiring.

scarey

• adj. Dated form of scary.

scary

• adj. Causing or able to cause fright.
• adj. (US, colloquial) Subject to sudden alarm; nervous, jumpy.
• n. Barren land having only a thin coat of grass.

shivery

• adj. Given to shivering; tending to shiver.
• adj. Easily broken; brittle.

shuddery

• adj. Characterized by shuddering motions.

sick

• adj. Having an urge to vomit.
• adj. (chiefly US) In poor health.
• adj. (colloquial) Mentally unstable, disturbed.
• adj. (colloquial) In bad taste.
• adj. Tired of or annoyed by something.
• adj. (slang) Very good, excellent, awesome, badass.
• adj. In poor condition.
• adj. (agriculture) Failing to sustain adequate harvests of crop, usually specified.
• n. Sick people in general as a group.
• n. (Britain, colloquial) vomit.
• v. To vomit.
• v. (obsolete, intransitive) To fall sick; to sicken.
• v. (rare) Alternative spelling of sic.

sinister

• adj. Inauspicious, ominous, unlucky, illegitimate (as in bar sinister).
• adj. Evil or seemingly evil; indicating lurking danger or harm.
• adj. Of the left side.
• adj. (heraldry) On the left side of a shield from the wearer's standpoint, and the right side to the viewer.
• adj. (obsolete) Wrong, as springing from indirection or obliquity; perverse; dishonest.

stupefying

• v. present participle of stupefy.

terrible

• adj. Dreadful; causing alarm and fear.
• adj. Formidable, powerful.
• adj. Intense; extreme in degree or extent.
• adj. Unpleasant; disagreeable.
• adj. Very bad; lousy.

terrific

• adj. (colloquial) Frighteningly good.
• adj. (colloquial) Astounding or awesome.
• adj. Terrifying; causing terror.
• adj. Frightful or very unpleasant.
• adj. (colloquial) Extraordinarily great or intense.

terrifying

• adj. Frightening or intimidating.
• adj. Of a formidable nature; terrific.
• v. present participle of terrify.

threatening

• v. present participle of threaten.
• adj. Presenting a threat; menacing; frightening.
• n. An act of threatening; a threat.

ugly

• adj. Displeasing to the eye; not aesthetically pleasing.
• adj. Displeasing to the ear or some other sense.
• adj. Offensive to one's sensibilities or morality.
• adj. Ill-natured; crossgrained; quarrelsome.
• adj. Unpleasant; disagreeable; likely to cause trouble or loss.
• n. (slang, uncountable) Ugliness.
• n. (slang) An ugly person or thing.
• n. (Britain, informal, dated) A shade for the face, projecting from a bonnet.
• v. (transitive, nonstandard) To make ugly (sometimes with up).

unnerving

• v. present participle of unnerve.