1. Ludicrously odd
   "fantastic Halloween costumes"
   - antic [archaic], fantastical, grotesque 
2. Extraordinarily good or great; used especially as an intensifier
   "a fantastic trip to the Orient"; "the film was fantastic!"
   - grand, howling, marvelous [US], marvellous [Brit, Cdn], rattling, terrific, tremendous, wonderful, wondrous 
3. Fanciful and unrealistic; foolish
   "a fantastic idea of his own importance"
   - wild 
4. Existing in fancy only
   "fantastic figures with bulbous heads the circumference of a bushel"
   - fantastical 
5. Extravagantly fanciful in design, construction, appearance
   "Gaudi's fantastic architecture"

See also: extraordinary, fancy, fantasy, strange, unreal, unrealistic, unusual

Encyclopedia: Fantastic

• zonal
• zonal pelargonium
• zonally
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• zone of interior
• zoning
• zoning board
• zoning commission
• zonk
• zonk out
• zonked
• zonked out
• Zonotrichia
• Zonotrichia albicollis
• Zonotrichia leucophrys
• zonula
• zonule
• zoo
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• zooerastia
• zooerasty
• zooflagellate
• zoogeography