fantastic

adj

1. 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!"”

2. 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.”

   “At the base of the whole process by which divinities and demons were created, and rites for their propitiation and placation established, lay Fear - fear stimulating the imagination to fantastic activity.”

3. (archaic)Not believable; implausible; seemingly only possible in fantasy.

   “Since 1 part in 100,000 would imply that one could put a Shuttle up each day for 300 years expecting to lose only one, we could properly ask "What is the cause of management's fantastic faith in the machinery?"”

4. (archaic)Resembling fantasies in irregularity, caprice, or eccentricity; irregular; grotesque.

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

   “[…]This round of green, this orb of flame, Fantastic beauty; such as lurks ⁠In some wild Poet, when he works Without a conscience or an aim.”

noun

1. (archaic)A fanciful or whimsical person.