WordNet (r) 3.0 (2006):

swallow up
    v 1: enclose or envelop completely, as if by swallowing; "The
         huge waves swallowed the small boat and it sank shortly
         thereafter" [syn: immerse, swallow, swallow up,
         bury, eat up]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "swallow up":
   ablate, absorb, assimilate, bleed white, bring to ruin, burn up,
   condemn, confound, consume, damn, deal destruction, decimate,
   deplete, depredate, desolate, despoil, destroy, devastate, devour,
   digest, dissolve, drain, drain of resources, eat, eat up, engorge,
   erode, exhaust, expend, finish, finish off, gobble, gobble up, gut,
   gut with fire, havoc, impoverish, incinerate, ingest, lay in ruins,
   lay waste, ravage, ruin, ruinate, shipwreck, spend, squander,
   suck dry, swallow, throw into disorder, unleash destruction,
   unleash the hurricane, upheave, use up, vandalize, vaporize, waste,
   waste away, wear away, wrack, wreak havoc, wreck