The Collaborative International Dictionary of English v.0.48:

Sacs \Sacs\ (s[add]ks), n. pl.; sing. Sac. (Ethnol.)
   A tribe of Indians, which, together with the Foxes, formerly
   occupied the region about Green Bay, Wisconsin. [Written also
   Sauks.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sac \Sac\ (s[add]k), n. (Ethnol.)
   See Sacs.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sac \Sac\, n. [See Sake, Soc.] (O.Eng. Law)
   The privilege formerly enjoyed by the lord of a manor, of
   holding courts, trying causes, and imposing fines. --Cowell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sac \Sac\ (s[a^]k), n. [F., fr. L. saccus a sack. See Sack a
   bag.]
   1. See 2d Sack.
      [1913 Webster]

   2. (Biol.) A cavity, bag, or receptacle, usually containing
      fluid, and either closed, or opening into another cavity
      to the exterior; a sack.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sac
    n 1: an enclosed space; "the trapped miners found a pocket of
         air" [syn: pouch, sac, sack, pocket]
    2: a case or sheath especially a pollen sac or moss capsule
       [syn: theca, sac]
    3: a member of the Algonquian people formerly living in
       Wisconsin in the Fox River valley and on the shores of Green
       Bay [syn: Sauk, Sac]
    4: a structure resembling a bag in an animal

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "SAC":
   ANAC, ARF, ATC, ATS, Air Command, Air Transport Command,
   Air Transport Service, Airborne Reconnaissance Force,
   Army-Navy Air Corps, Bomber Command, CASU, Coastal Command, FEAF,
   Fleet Air Arm, MATS, NAD, NATS, Naval Air Division, Navy Air, RAAF,
   RAF, RCAF, Royal Air Force, Strategic Air Command, US Air Force,
   USAAF, USAF, USNAS, air force



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAC
       Service / Special Area Code


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAC
       Single Attachment Concentrator (FDDI)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAC
       Spatial Audio Coding


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAC
       Strict Avalanche Criterion (cryptography)


The Free On-line Dictionary of Computing (30 December 2018):

SAC

   1. An early system on the Datatron 200 series.

   [Listed in CACM 2(5):16 (May 1959)].

   (1995-04-12)

   2. Service Access Controller.

   (2002-12-30)


U.S. Gazetteer Counties (2000):

Sac -- U.S. County in Iowa
   Population (2000):    11529
   Housing Units (2000): 5460
   Land area (2000):     575.822650 sq. miles (1491.373754 sq. km)
   Water area (2000):    2.561683 sq. miles (6.634728 sq. km)
   Total area (2000):    578.384333 sq. miles (1498.008482 sq. km)
   Located within:       Iowa (IA), FIPS 19
   Location:             42.381921 N, 95.093223 W
   Headwords:
    Sac
    Sac, IA
    Sac County
    Sac County, IA