The Collaborative International Dictionary of English v.0.48:

Sack \Sack\, v. t. [imp. & p. p. Sacked; p. pr. & vb. n.
   Sacking.] [See Sack pillage.]
   To plunder or pillage, as a town or city; to devastate; to
   ravage.
   [1913 Webster]

         The Romans lay under the apprehensions of seeing their
         city sacked by a barbarous enemy.        --Addison.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sacking \Sack"ing\, n. [AS. saeccing, from saecc sack, bag.]
   Stout, coarse cloth of which sacks, bags, etc., are made.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sacking
    n 1: coarse fabric used for bags or sacks [syn: sacking,
         bagging]
    2: the termination of someone's employment (leaving them free to
       depart) [syn: dismissal, dismission, discharge,
       firing, liberation, release, sack, sacking]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "sacking":
   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, pillaging, plunder,
   plundering, raid, raiding, ransacking, rape, rapine, ravage,
   ravagement, ravaging, ravishment, razzia, reiving, rifling, riot,
   rioting, sack, slaughter, sowing with salt, spoiling, spoliation,
   unruliness, violation