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]