The Collaborative International Dictionary of English v.0.48:

Campanile \Cam`pa*ni"le\, n. [It. campanile bell tower, steeple,
   fr. It. & LL. campana bell.] (Arch.)
   A bell tower, esp. one built separate from a church.
   [1913 Webster]

         Many of the campaniles of Italy are lofty and
         magnificent structures.                  --Swift.
   [1913 Webster]

WordNet (r) 3.0 (2006):

campanile
    n 1: a bell tower; usually stands alone unattached to a building
         [syn: campanile, belfry]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "campanile":
   antenna tower, barbican, belfry, bell tower, carillon, colossus,
   column, cupola, derrick, dome, fire tower, lantern, lighthouse,
   martello, martello tower, mast, minaret, monument, obelisk,
   observation tower, pagoda, pilaster, pillar, pinnacle, pole, pylon,
   pyramid, shaft, skyscraper, spire, standpipe, steeple, stupa,
   television mast, tope, tour, tower, turret, water tower,
   windmill tower