The Collaborative International Dictionary of English v.0.48:

Pillage \Pil"lage\, v. i. [imp. & p. p. Pillaged; p. pr. & vb.
   n. Pillaging.]
   To strip of money or goods by open violence; to plunder; to
   spoil; to lay waste; as, to pillage the camp of an enemy.
   [1913 Webster]

         Mummius . . . took, pillaged, and burnt their city.
                                                  --Arbuthnot.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pillaging
    n 1: the act of stealing valuable things from a place; "the
         plundering of the Parthenon"; "his plundering of the great
         authors" [syn: plundering, pillage, pillaging]

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "pillaging":
   assault, attack, banditry, battering, brigandage, brigandism,
   butchery, depredation, despoiling, despoilment, despoliation,
   direption, disorderliness, foraging, foray, forcible seizure,
   freebooting, killing, laying waste, looting, marauding, massacre,
   obstreperousness, onslaught, pillage, plunder, plundering,
   plunderous, predacious, predacity, predatory, raid, raiding,
   ransacking, rapaciousness, rapacity, rape, rapine, ravage,
   ravagement, ravaging, ravenousness, ravishment, razzia, reiving,
   rifling, riot, rioting, sack, sacking, sharkishness, slaughter,
   sowing with salt, spoiling, spoliation, spoliatory, unruliness,
   violation, wolfishness