What's the adjective for frightening? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs fright and frighten which may be used as adjectives within certain contexts.
“My only fear is that it's so easy to laugh at politicians and their idiot supporters that you risk forgetting how evil and stupid they really are, allowing them to stumble their way into a frightful mess we all end up having to pay for.”
“Electromagnetic pollution, which has been described as a serious killer in the office, actually is not frightful at all, say experts.”
“The thunderstorm was frightful, with lightning striking every few seconds and winds reaching hurricane force.”