Nouns

(n)visionarya person given to fanciful speculations and enthusiasms with little regard for what is actually possible
(n)visionary, illusionist, seera person with unusual powers of foresight

Adjectives

(s)airy, impractical, visionary, Laputan, windynot practical or realizable; speculative“airy theories about socioeconomic improvement”, “visionary schemes for getting rich”