Adjective

(en-adj)

Dreadful; causing alarm and fear.

Formidable, powerful.

* 1883: (Robert Louis Stevenson), (Treasure Island)

and there was even a party of the younger men who pretended to admire him, calling him a "true sea-dog," and "real old salt," and such-like names, and saying there was the sort of man that made England terrible at sea.

Intense; extreme in degree or extent.

* {{quote-book, year=1963, author=(Margery Allingham), title=(The China Governess)

, chapter=18 citation , passage=‘Then the father has a great fight with his terrible conscience,’ said Munday with granite seriousness. ‘Should he make a row with the police […]? Or should he say nothing about it and condone brutality for fear of appearing in the newspapers?}}

Unpleasant; disagreeable.

* , chapter=12

, title= The Mirror and the Lamp , passage=To Edward […] he was terrible , nerve-inflaming, poisonously asphyxiating. He sat rocking himself in the late Mr. Churchill's swing chair, smoking and twaddling.}}

Very bad; lousy.

* {{quote-news, year=2012, date=April 26, author=Tasha Robinson, work=The Onion AV Club

, title= Film: Reviews: The Pirates! Band Of Misfits , passage=The openly ridiculous plot has The Pirate Captain (Hugh Grant) scheming to win the Pirate Of The Year competition, even though he’s a terrible pirate, far outclassed by rivals voiced by Jeremy Piven and Salma Hayek.}}

Adjective

(en adjective)

Existing in or constructed from fantasy; of or relating to fantasy; fanciful.

He told fantastic stories of dragons and goblins.

His fantastic post-college plans had all collapsed within a year of graduation.

She had a fantastic view of her own importance that none of her colleagues shared.

Not believable; implausible; seemingly only possible in fantasy.

The events were so fantastic that only the tabloids were willing to print them.

She entered the lab and stood gaping for a good ten minutes at the fantastic machinery at work all around her.

Resembling fantasies in irregularity, caprice, or eccentricity; irregular; grotesque.

* T. Gray

There at the foot of yonder nodding beech, / That wreathes its old fantastic roots so high.

Wonderful; marvelous; excellent; extraordinarily good or great (used especially as an intensifier ).

"I had a simply fantastic vacation, and I can't wait to tell you all about it!"