The Collaborative International Dictionary of English v.0.48:

Detach \De*tach"\, v. i.
   To push asunder; to come off or separate from anything; to
   disengage.
   [1913 Webster]

         [A vapor] detaching, fold by fold,
         From those still heights.                --Tennyson.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Detach \De*tach"\, v. t. [imp. & p. p. Detached; p. pr. & vb.
   n. Detaching.] [F. d['e]tacher (cf. It. distaccare,
   staccare); pref. d['e] (L. dis) + the root found also in E.
   attach. See Attach, and cf. Staccato.]
   1. To part; to separate or disunite; to disengage; -- the
      opposite of attach; as, to detach the coats of a bulbous
      root from each other; to detach a man from a leader or
      from a party.
      [1913 Webster]

   2. To separate for a special object or use; -- used
      especially in military language; as, to detach a ship from
      a fleet, or a company from a regiment.

   Syn: To separate; disunite; disengage; sever; disjoin;
        withdraw; draw off. See Detail.
        [1913 Webster]

WordNet (r) 3.0 (2006):

detach
    v 1: cause to become detached or separated; take off; "detach
         the skin from the chicken before you eat it" [ant:
         attach]
    2: separate (a small unit) from a larger, especially for a
       special assignment; "detach a regiment"
    3: come to be detached; "His retina detached and he had to be
       rushed into surgery" [syn: detach, come off, come away]
       [ant: attach]