- Main Entry:
- 1ir·ra·tio·nal

- Pronunciation:
-
\i-ˈra-sh(ə-)nəl, ˌi(r)-\
- Function:
- adjective
- Etymology:
- Middle English, from Latin irrationalis, from in- + rationalis rational
- Date:
- 14th century
: not rational: as a (1): not endowed with reason or understanding (2): lacking usual or normal mental clarity or coherence b: not governed by or according to reason <irrational fears> cGreek & Latin prosody (1)of a syllable : having a quantity other than that required by the meter (2)of a foot : containing such a syllable d (1): being an irrational number <an irrational root of an equation> (2): having a numerical value that is an irrational number <a length that is irrational>
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ir·ra·tio·nal·i·ty
\-ˌra-shə-ˈna-lə-tē\ noun
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ir·ra·tio·nal·ly
\-ˈra-sh(ə-)nə-lē\ adverb