The Collaborative International Dictionary of English v.0.48:

Maximum \Max"i*mum\, n.; pl. Maxima. [L., neut. from maximus
   the greatest. See Maxim.]
   The greatest quantity or value attainable in a given case;
   or, the greatest value attained by a quantity which first
   increases and then begins to decrease; the highest point or
   degree; -- opposed to minimum.
   [1913 Webster]

         Good legislation is the art of conducting a nation to
         the maximum of happiness, and the minimum of misery.
                                                  --P.
                                                  Colquhoun.
   [1913 Webster]

   Maximum thermometer, a thermometer that registers the
      highest degree of temperature attained in a given time, or
      since its last adjustment.
      [1913 Webster]