<p><strong>Adjective</strong></p><ul><li>below the normal</li><li>less than or inferior to the normal</li><li>a subnormal amount of rain</li><li>being less than average in any psychological trait, as intelligence, personality, or emotional adjustment</li></ul><p><strong>Noun</strong></p><ul><li>a subnormal person</li></ul><p><strong>Geometry Description</strong></p><ul><li>that part of the x-axis of a curve cut off between the ordinate and a normal.</li></ul>