How to say "impractical" in Japanese

• 非実際的ひじっさいてき
  na-adjectiveCovers ideas or methods that do not work well in real-life practice. Its nuance is close to 非現実的, but it is less common, so learners will usually want 非現実的 instead.
• 非現実的ひげんじつてき
  na-adjectiveThe standard word for plans, ideas, or proposals that are unrealistic and cannot realistically be carried out. Use this when 'impractical' means too idealistic or simply not feasible in the real world.
  いつものごとく、彼かれの考かんがえはあまりに非ひ現実的げんじつてきだった。↗

  As usual, his thoughts were extremely academic.
• 迂遠うえん
  na-adjectiveReally means roundabout or circuitous; it describes routes, procedures, or approaches that take an indirect path. 'Impractical' appears among its glosses, but it is a marginal fit and seldom the word you want for that sense.

For 'impractical' in the sense of not workable or too idealistic, 非現実的 is the usual choice; 非実際的 is a close variant, while 迂遠 means roundabout and only loosely fits.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 非実際的ひじっさいてきimpractical
• 非現実的ひげんじつてきunrealistic
• 迂遠うえんroundabout