The Collaborative International Dictionary of English v.0.48:

Sweeping \Sweep"ing\, a.
   Cleaning off surfaces, or cleaning away dust, dirt, or
   litter, as a broom does; moving with swiftness and force;
   carrying everything before it; including in its scope many
   persons or things; as, a sweeping flood; a sweeping majority;
   a sweeping accusation. -- Sweep"ing*ly, adv.
   -Sweep"ing*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sweepingly
    adv 1: in a sweeping manner; "he sweepingly condemned the entire
           population of the country for the war crimes"