quixotic ideal
/kwɪkˈsɒtɪk aɪˈdiːəl/
noun phrase
-
A noble or idealistic but impractical and unrealistic goal or ambition that is unlikely to succeed in the real world.
B2formal
- "He has a quixotic ideal of creating a world without war."B2
- "Trying to eliminate all political disagreement may be a quixotic ideal, but it can still inspire useful reforms."C1