FRIGHTENING
awful, dire, direful, dread, dreaded, dreadful, fearful, fearsome, frightening, horrendous, horrific, terrible
(adjective) causing fear or dread or terror; “the awful war”; “an awful risk”; “dire news”; “a career or vengeance so direful that London was shocked”; “the dread presence of the headmaster”; “polio is no longer the dreaded disease it once was”; “a dreadful storm”; “a fearful howling”; “horrendous explosions shook the city”; “a terrible curse”
terrorization, terrorisation, frightening
(noun) the act of inspiring with fear
Source: WordNet® 3.1
Etymology
Adjective
frightening (comparative more frightening, superlative most frightening)
Causing fear; of capable of causing fear; scary.
(figuratively) Awful, terrible, very bad.
Synonyms
• frightening
Verb
frightening
present participle of frighten
Source: Wiktionary
FRIGHTEN
Fright"en, v. t. [imp. Frightened; p. pr. & vb. n. Frightening.]
Etym: [See Fright, v. t.]
Definition: To disturb with fear; to throw into a state of alarm or fright;
to affright; to terrify.
More frightened than hurt. Old Proverb.
Source: Webster’s Unabridged Dictionary 1913 Edition