21
mind-altering(adjective, characteristic, emotions, sensations)
21
psychedelic(adjective, characteristic, emotions, sensations)
21
staggering(adjective, characteristic, emotions, sensations)
20
dreadful(adjective, awful, terrible, fear, horrible)
19
horrifying(verb, adjective, awful, wonderful, foul)
19
terrifying(verb, adjective, awful, shocking, dangerous)
18
appalling(adjective, awful, frightful)
15
awful(adjective, bad, awful, terrible, fear)
15
dire(adjective, awful, terrible, fear, shocking)
12
terrible(adjective, bad, awful, heavy, fear)
12
frightful(adjective, unpleasant, awful, terrible, foul)
12
horrible(adjective, awful, terrible, fear, foul)
11
dismaying(verb, adjective, hard, severe, offensive)
10
disturbing(verb, adjective, hard, severe, upsetting)
10
formidable(adjective, bad, awful, heavy, fear)
10
threatening(verb, adjective, bad, warning, danger)
9
daunting(adjective, awful, terrible, wonderful, disgusting)
9
dread(adjective, fear, horrible, shocking, upsetting)
9
ghastly(adjective, awful, fear)
9
unnerving(verb, adjective, awful, terrible, disgusting)
10 years ago|12k views|share |citing 
APASmart Define. (2016). alarming thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/alarming/thesaurus/synonyms
ChicagoSmart Define. 2016. "alarming thesaurus" https://smartdefine.org/alarming/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, alarming thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/alarming/thesaurus/synonyms>.
MLASmart Define. "alarming thesaurus" 3 April 2016. Web. 20 September 2026. <https://smartdefine.org/alarming/thesaurus/synonyms>