The Collaborative International Dictionary of English v.0.48:

Centigrade \Cen"ti*grade\, a. [L. centum a hundred + gradus
   degree: cf. F. centigrade.]
   Consisting of a hundred degrees; graduated into a hundred
   divisions or equal parts. Specifically: Of or pertaining to
   the centigrade thermometer; as, 10[deg] centigrade (or
   10[deg] C.). In measurements, abreviated C.
   [1913 Webster]

   Centigrade thermometer, a thermometer having the zero or 0
      at the point indicating the freezing state of water, and
      the distance between that and the point indicating the
      boiling state of water divided into one hundred degrees.
      It is called also the Celsius thermometer, from Anders
      Celsius, the originator of this scale. Measurements are
      reported as [deg] C.
      [1913 Webster] Centigram