IRRATIONAL

I. adjective Etymology: Middle English, from Latin ~is, from in- + rationalis rational Date: 14th century not rational: as, a. not endowed with reason or understanding, lacking usual or normal mental clarity or coherence, not governed by or according to reason , c. Greek & Latin prosody having a quantity other than that required by the meter, containing such a syllable, d. being an ~ number , having a numerical value that is an ~ number , ~ity noun ~ly adverb II. noun Date: 1646 an ~ being, ~ number