1. [n]  someone who has won first place in a competition
2. [v]  chew noisily
3. [v]  chafe at the bit, of horses

CHAMP is a 5 letter word that starts with C.

1. \Champ\, v. t. [imp. & p. p. {Champed}; p. pr. & vb. n.
   {Champing}.] [Prob, of Scand. orgin; cf. dial. Sw. k["a]msa
   to chew with difficulty, champ; but cf. also OF. champier,
   champeyer, champoyer, to graze in fields, fr. F. champ field,
   fr. L. campus. Cf. {Camp}.]
   1. To bite with repeated action of the teeth so as to be
      heard.
   
            Foamed and champed the golden bit.    --Dryden.
   
   2. To bite into small pieces; to crunch. --Steele.
   
   

2. \Champ\, v. i.
   To bite or chew impatiently.
   
         They began . . . irefully to champ upon the bit.
                                                  --Hooker.
   
   

3. \Champ\, Champe \Champe\, n. [F. champ, L. campus field.]
   (Arch.)
   The field or ground on which carving appears in relief.