Source : Webster's Revised Unabridged Dictionary (1913)

Turndown \Turn"down`\, a.
   1. Capable of being turned down; specif. (Elec.),
      designating, or pertaining to, an incandescent lamp with a
      small additional filament which can be made incandescent
      when only a small amount of light is required.

   2. Made to wear with the upper part turned down; as, a
      turndown collar.

Source : WordNet®

turndown
     n : the act of refusing an offer; "the turndown was polite but
         very firm" [syn: {nonacceptance}]