非合理|ひごうりhigouri[2]nakadaka (mid-high)

1. na-adjective, nounillogicality

• Synonym不合理ふごうりNeutralEveryday word for rules or practices that make no sense; often carries a sense of dissatisfaction, as in 「不合理な規則」. More colloquial than 「非合理」.
• Synonym不条理ふじょうりWrittenWritten/formal prose for what defies social common sense; also the absurd in philosophy, as in 「不条理劇」.
• Synonym理不尽りふじんNeutralFor demands or treatment that are utterly without reason; carries strong indignation and is more emotional than 「非合理」.
• Synonym非論理的ひろんりてきWrittenWritten/formal prose; stresses that the reasoning or line of argument does not hold up. Very close in sense to 「非合理」.
• Related盲目もうもくNeutralAlso means loss of eyesight. About conduct, it stresses acting recklessly without grasping the situation, and is more negative than 「非合理」.
• Related盲目的もうもくてきWrittenWritten/formal prose; losing reason and believing or obeying without thinking, as in 「盲目的な愛」.
• Related盲滅法めくらめっぽうCasualColloquial for doing something wildly without thinking; contains a discriminatory word for 'blind', so it is now largely avoided.
• Related迷信的なWrittenWritten/formal prose; believing claims that have no basis, a concrete instance of the irrational.
• Antonym合理ごうりNeutralDirect antonym: being in accord with reason and logic, the opposite of unreasonable 「非合理」.
• Antonym理性的りせいてきWrittenWritten/formal prose; judging calmly by reason, the opposite of illogical, unreasonable 「非合理」.

Use 「非合理」 for what defies logic and cannot be explained rationally; it belongs to written/formal prose, as in 「非合理な判断」「非合理な感情」. For everyday unreasonableness pick 「不合理」; for outrageous, high-handed unreasonableness 「理不尽」. 「合理」 and 「理性的」 are its antonyms.

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

1. 論理的ろんりてきではなく、筋道すじみちが通かよっていない様子ようす。