The Collaborative International Dictionary of English v.0.48:

enclosed \enclosed\ adj.
   surrounded or closed in, usually on all sides. Opposite of
   unenclosed. [Narrower terms: basined; capsulate,
   capsulated; closed, closed in(predicate); coarctate;
   confined, fenced in, penned; embedded, fixed; embedded,
   surrounded; encircled; enveloped; fogbound;
   self-enclosed; surrounded, encircled]
   [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

enveloped \enveloped\ adj.
   enclosed or surrounded completely; as, the fog-enveloped
   city.
   [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Envelop \En*vel"op\, v. t. [imp. & p. p. Enveloped; p. pr. &
   vb. n. Enveloping.] [OE. envolupen, envolipen, OF.
   envoluper, envoleper, F. envelopper; pref. en- (L. in) +
   voluper, voleper. See Develop.]
   To put a covering about; to wrap up or in; to inclose within
   a case, wrapper, integument or the like; to surround
   entirely; as, to envelop goods or a letter; the fog envelops
   a ship.
   [1913 Webster]

         Nocturnal shades this world envelop.     --J. Philips.
   Envelope