The Collaborative International Dictionary of English v.0.48:

Round-up \Round"-up`\, n.
   1. The act of collecting or gathering together scattered
      cattle by riding around them and driving them in. [Western
      U.S.]
      [1913 Webster]

   2. A rounding up, or upward curvature or convexity, as in the
      deck of a vessel.
      [Webster 1913 Suppl.]

   2. A gathering in of scattered persons or things; as, a
      round-up of criminals. [Colloq., U. S.]
      [Webster 1913 Suppl.]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "roundup":
   assemblage, assembly, call-up, canvass, census, collection,
   colligation, collocation, combination, comparison, concourse,
   concurrence, confluence, conflux, congregation, convergence,
   corralling, data-gathering, gathering, ingathering, inventory,
   junction, juxtaposition, mobilization, muster, rodeo, survey



U.S. Gazetteer Places (2000):

Roundup, MT -- U.S. city in Montana
   Population (2000):    1931
   Housing Units (2000): 978
   Land area (2000):     1.343016 sq. miles (3.478396 sq. km)
   Water area (2000):    0.001627 sq. miles (0.004214 sq. km)
   Total area (2000):    1.344643 sq. miles (3.482610 sq. km)
   FIPS code:            64525
   Located within:       Montana (MT), FIPS 30
   Location:             46.448401 N, 108.542676 W
   ZIP Codes (1990):     59072
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Roundup, MT
    Roundup