non-rational
|non-ra-tion-al|
🇺🇸
/nɑnˈræʃənəl/
🇬🇧
/nɒnˈræʃ(ə)nəl/
not based on reason / not rational
Etymology
'non-rational' originates from Latin and English elements: specifically the prefix 'non-' (from Latin 'non' meaning 'not') combined with 'rational' from Latin 'rationalis' (from 'ratio' meaning 'reason' or 'calculation').
'rational' came from Latin 'rationalis' (pertaining to reason) and entered English via Old French/Medieval Latin into Middle English as 'rational'; the negative prefix 'non-' was later attached in Modern English to form 'non-rational'.
Initially 'rational' meant 'pertaining to reason'; adding the negative 'non-' originally produced a straightforward negation 'not pertaining to reason.' Over time the compound has kept that general sense and is also used in technical contexts (e.g., mathematics) to mean 'not rational' (i.e., irrational).
Meanings by Part of Speech
Adjective 1
not based on reason or logical thought; lacking rational justification; unreasonable.
The committee's decision seemed non-rational given the evidence.
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Adjective 2
in mathematics, not rational; not expressible as a ratio of two integers (i.e., an irrational number).
Sqrt(2) is a non-rational number.
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Last updated: 2025/12/22 02:17