The Collaborative International Dictionary of English v.0.48:

Rebuff \Re*buff"\, v. t. [imp. & p. p. Rebuffed
   (r[-e]*b[u^]ft"); p. pr. & vb. n. Rebuffing.]
   To beat back; to offer sudden resistance to; to check; to
   repel or repulse violently, harshly, or uncourteously.
   [1913 Webster] re-build