Source : Webster's Revised Unabridged Dictionary (1913)

Brutalize \Bru"tal*ize\, v. t. [imp. & p. p. {Brutalized}; p.
   pr. & vb. n. {Brutalizing}.] [Cf. F. brutaliser.]
   To make brutal; beasty; unfeeling; or inhuman.

Brutalize \Bru"tal*ize\, v. i.
   To become brutal, inhuman, barbarous, or coarse and beasty.
   [R.]

         He mixed . . . with his countrymen, brutalized with
         them in their habits and manners.        --Addison.

Source : WordNet®

brutalize
     v 1: treat brutally [syn: {brutalise}]
     2: make brutal, unfeeling, or inhuman; "Life in the camps had
        brutalized him" [syn: {brutalise}, {animalize}, {animalise}]
     3: become brutal or insensitive and unfeeling [syn: {brutalise},
         {animalize}, {animalise}]