Source : Webster's Revised Unabridged Dictionary (1913)

Bustling \Bus"tling\ (b[u^]s"sl[i^]ng), a.
   Agitated; noisy; tumultuous; characterized by confused
   activity; as, a bustling crowd. ``A bustling wharf.''
   --Hawthorne.

Bustle \Bus"tle\ (b[u^]s"s'l), v. i. [imp. & p. p. {Bustled}
   (-s'ld); p. pr. & vb.n. {Bustling} (-sl[i^]ng).] [Cf. OE.
   buskle, perh. fr. AS. bysig busy, bysg-ian to busy + the
   verbal termination -le; or Icel. bustla to splash, bustle.]
   To move noisily; to be rudely active; to move in a way to
   cause agitation or disturbance; as, to bustle through a
   crowd.

         And leave the world for me to bustle in. --Shak.

Source : WordNet®

bustling
     adj : full of energetic and noisy activity; "a bustling city"