The Collaborative International Dictionary of English v.0.48:

Fetter \Fet"ter\ (f[e^]t"t[~e]r), n. [AS. fetor, feter; akin to
   OS. feter[=o]s, pl., OD. veter, OHG. fezzera, Icel.
   fj["o]turr, L. pedica, Gr. pe`dh, and to E. foot. [root] 77.
   See Foot.] [Chiefly used in the plural, fetters.]
   1. A chain or shackle for the feet; a chain by which an
      animal is confined by the foot, either made fast or
      disabled from free and rapid motion; a bond; a shackle.
      [1913 Webster]

            [They] bound him with fetters of brass. --Judg. xvi.
                                                  21.
      [1913 Webster]

   2. Anything that confines or restrains; a restraint.
      [1913 Webster]

            Passion's too fierce to be in fetters bound.
                                                  --Dryden.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

FETTERS. A sort of iron put on the legs of malefactors, or persons accused
of crimes.
     2. When a prisoner is brought into court to plead he shall not be put
in fetters. 2 Inst. 315; 3 Inst. 34; 2 Hale, 119; Hawk. b. 21 c. 28, s. 1
Kel. 10; 1 Chitty's Cr. Law, 417. An officer having arrested a defendant on
a civil suit, or a person accused of a crime, has no right to handcuff him
unless it is necessary, or he has attempted to make his escape. 4 B. & C.
596; 10 Engl. C. L. Rep. 412, S. C.