Adjective
1. ludicrously odd;
"Hamlet's assumed antic disposition""fantastic Halloween costumes""a grotesque reflection in the mirror"2. extraordinarily good; used especially as intensifiers;
"a fantastic trip to the Orient""the film was fantastic!""a howling success""a marvelous collection of rare books""had a rattling conversation about politics""a tremendous achievement"3. extravagantly fanciful and unrealistic; foolish;
"a fantastic idea of his own importance"4. existing in fancy only;
"fantastic figures with bulbous heads the circumference of a bushel"- Nathaniel Hawthorne5. exceedingly or unbelievably great;
"the bomb did fantastic damage""Samson is supposed to have had fantastic strength""phenomenal feats of memory"