The Collaborative International Dictionary of English v.0.48:

Cauter \Cau"ter\, n. [F. caut[`e]re, L. cauterium, fr. Gr. ? a
   branding iron, fr. ? to burn. Cf. Caustic, Cautery.]
   A hot iron for searing or cauterizing. --Minsheu.
   [1913 Webster]