The Collaborative International Dictionary of English v.0.48:

Incurve \In*curve"\ ([i^]n*k[^u]v"), v. t. [imp. & p. p.
   Incurved ([i^]n*k[^u]vd"); p. pr. & vb. n. Incurving.]
   [See Incurvate.]
   To bend; to curve; to make crooked.
   [1913 Webster]