The Collaborative International Dictionary of English v.0.48:

Roughen \Rough"en\, v. t. [imp. & p. p. Roughened; p. pr. &
   vb. n. Roughening.] [From Rough.]
   To make rough.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Roughen \Rough"en\, v. i.
   To grow or become rough.
   [1913 Webster]

WordNet (r) 3.0 (2006):

roughen
    v 1: make rough or rougher; "roughen the surfaces so they will
         stick to each other" [ant: smooth, smoothen]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "roughen":
   agitate, beat, beat up, boss, churn, churn up, coarsen, convulse,
   disarrange, discompose, disquiet, disturb, excite, ferment, flurry,
   fret, gnarl, grain, granulate, horripilate, knob, paddle, perturb,
   perturbate, pimple, rile, ripple, roil, rough, rough up, ruffle,
   rumple, shake, shake up, smooth, stir, stir up, stud, swirl, tooth,
   trouble, upset, whip, whip up, whisk, work up