n :  the point at which a physiological or psychological effect begins to be produced (as the degree of stimulation of a nerve which just produces a response or the concentration of sugar in the blood at which sugar just begins to pass the barrier of the kidneys and enter the urine) <below the of consciousness>  <the of pain>  <a high renal clearance >  - called also limen  .
 
 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2004.