impractical
im-prac-ti-cal
adjective
Not sensible or realistic; difficult to implement or use effectively.
"His grand scheme was utterly impractical."
Thesaurus
Synonyms: wild-eyed, screwball, unwieldy, quixotic, meshuggeneh, half-baked, meshuga, meshuggener, romantic, unfunctional, softheaded, meshugga
Antonyms: practical