utopian

Short definition from Wiktionary

Adjective

1. 1
   Of or pertaining to or resembling a utopia.
2. 2
   Ideal but often impractical; visionary.
3. 3
   Alternative letter-case form of utopian.

Noun

1. 1
   Someone who supports or heralds the establishment of a utopia.
2. 2
   Alternative letter-case form of utopian.
3. 3
   A person from Utopia, a fictional island possessing a seemingly perfect socio-politico-legal system from Thomas More’s 1516 treatise of the same name.

Proper noun

1. 1
   A constructed language created by Thomas More and Peter Giles for the fictional island Utopia, from 1516 Thomas More’s book of the same name.