The Collaborative International Dictionary of English v.0.48:

Bray \Bray\ (br[=a]), v. t. [imp. & p. p. Brayed (br[=a]d); p.
   pr. & vb. n. Braying.] [OE. brayen, OF. breier, F. broyer
   to pound, grind, fr. OHG. brehhan to break. See Break.]
   To pound, beat, rub, or grind small or fine.
   [1913 Webster]

         Though thou shouldest bray a fool in a mortar, . . .
         yet will not his foolishness depart from him. --Prov.
                                                  xxvii. 22.
   [1913 Webster]