1. graded adjective & adjective Frightful means very bad or unpleasant. [old-fashioned] ⇒ My father was unable to talk about the war, it was so frightful. 2. adjective [ADJ n] Frightful is used to emphasize the extent or degree of something, usually something bad. [informal, old-fashioned, emphasis] ⇒ He got himself into a frightful muddle. ⇒ What frightful gossips people are, even one's best friends. frightfully
adverb [ADV adj/adv] terribly ⇒ I'm most frightfully sorry about this. ⇒ You're frightfully good at this sort of thing.
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