The Collaborative International Dictionary
Fantasticism
Fantasticism \Fan*tas"ti*cism\, n.
The quality of being fantastical; fancifulness; whimsicality.
--Ruskin.
Wiktionary
fantasticism
n. The quality of being fantastical; whimsicality.
Usage examples of "fantasticism".
For extreme fantasticisms the best authorities I know are Rabelais and the late Artemus Ward.