from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Causing disgust or shock; horrifying.
- adj. Causing fright; terrifying.
- adj. Informal Excessive; extreme: a frightful liar.
- adj. Informal Disagreeable; distressing: frightful weather.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. : Full of fright; affrighted; frightened.
- adj. Full of that which causes fright; exciting alarm; impressing terror; shocking; as, a frightful chasm, or tempest; a frightful appearance.
- adj. Used as an intensifier
from the GNU version of the Collaborative International Dictionary of English
- adj. Full of fright; affrighted; frightened.
- adj. Full of that which causes fright; exciting alarm; impressing terror; shocking.
from The Century Dictionary and Cyclopedia
- Full of occasion for fright; causing or apt to excite alarm or terror; terrible; dreadful: as, a frightful chasm; a frightful tempest.
- Intolerable; shocking; hideous.
- Full of terror; fearful; alarmed.
- Synonyms Dreadful, Fearful, etc. (see awful); alarming, terrific, horrible, shocking.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. extreme in degree or extent or amount or impact
- adj. provoking horror
- adj. extremely distressing
From Middle English frightful ("afraid"), from Old English forhtful ("fainthearted, timorous"), equivalent to fright + -ful. (Wiktionary)