WordNet (r) 3.0 (2006):

steamroller
    n 1: a massive inexorable force that seems to crush everything
         in its way [syn: juggernaut, steamroller]
    2: vehicle equipped with heavy wide smooth rollers for
       compacting roads and pavements [syn: steamroller, road
       roller]
    v 1: bring to a specified state by overwhelming force or
         pressure; "The Senator steamrollered the bill to defeat"
         [syn: steamroller, steamroll]
    2: proceed with great force; "The new teacher tends to
       steamroller" [syn: steamroller, steamroll]
    3: crush with a steamroller as if to level; "steamroller the
       road"
    4: overwhelm by using great force; "steamroller the opposition"
       [syn: steamroller, steamroll]
    5: make level or flat with a steamroller; "steamroll the roads"
       [syn: steamroll, steamroller]

Moby Thesaurus II by Grady Ward, 1.0:

108 Moby Thesaurus words for "steamroller":
   align, beat, beat down, big battalions, blackjack, blank, blast,
   blow down, bludgeon, break down, bring down, brute force, bulldoze,
   bulldozer, bully, burn down, cast down, cheese grater, chop down,
   clobber, coerce, coercive, comminutor, cream, crusher, cut down,
   defeat utterly, dragoon, drub, equalize, even, fell, flatten,
   flush, force, forcible, grade, granulator, grater, grinder, hijack,
   intimidate, knock down, knock over, kominuter, lambaste, lay,
   lay down, lay flat, lay level, lay low, lay out, level, levigator,
   lick, main force, masher, mill, millstone, mortar and pestle,
   mow down, naked force, nutmeg grater, overbear, overwhelm, paste,
   pestle, physical force, prostrate, pull down, pulverizer, quern,
   quernstone, rase, raze, rock crusher, roll, roll flat, roller,
   rule of might, schmear, shanghai, shellac, shredder, shut out,
   skunk, sledgehammer, smash, smear, smooth, smooth out, smoothen,
   snow under, steamroll, strong-arm, take down, tear down,
   throw down, triturator, tyranny, ultima ratio, use violence,
   violent, wallop, whelm, whitewash, whomp, whop