Dictionary

A fanciful or whimsical person.

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

Example: He told fantastic stories of dragons and goblins.

Not believable; implausible; seemingly only possible in fantasy.

Example: 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.

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

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