The Collaborative International Dictionary of English v.0.48:

Llano \Lla"no\, n.; pl. Llanos. [Sp., plain even, level. See
   Plain.]
   An extensive plain with or without vegetation. [Spanish
   America]
   [1913 Webster]

WordNet (r) 3.0 (2006):

llano
    n 1: an extensive grassy and nearly treeless plain (especially
         in Latin America)

Moby Thesaurus II by Grady Ward, 1.0:

71 Moby Thesaurus words for "llano":
   alkali flat, alluvial plain, basin, bottomland, bushveld, campo,
   champaign, champaign country, coastal plain, delta, desert, down,
   downs, fell, flat, flat country, flatland, flats, grass,
   grass veld, grassland, grazing, haugh, haughland, heath, lande,
   lea, level, lowland, lowlands, lunar mare, mare, mead, meadow,
   meadow land, mesa, mesilla, moor, moorland, open country, pampa,
   pampas, park, pasturage, pasture, pasture land, peneplain, plain,
   plains, plateau, playa, prairie, range, salt flat, salt marsh,
   salt pan, savanna, sebkha, steppe, steppeland, swale, table,
   tableland, tree veld, tundra, upland, vega, veld, weald,
   wide-open spaces, wold



U.S. Gazetteer Counties (2000):

Llano -- U.S. County in Texas
   Population (2000):    17044
   Housing Units (2000): 11829
   Land area (2000):     934.764234 sq. miles (2421.028149 sq. km)
   Water area (2000):    31.411646 sq. miles (81.355785 sq. km)
   Total area (2000):    966.175880 sq. miles (2502.383934 sq. km)
   Located within:       Texas (TX), FIPS 48
   Location:             30.706247 N, 98.555445 W
   Headwords:
    Llano
    Llano, TX
    Llano County
    Llano County, TX


U.S. Gazetteer Places (2000):

Llano, TX -- U.S. city in Texas
   Population (2000):    3325
   Housing Units (2000): 1539
   Land area (2000):     4.444713 sq. miles (11.511754 sq. km)
   Water area (2000):    0.255361 sq. miles (0.661382 sq. km)
   Total area (2000):    4.700074 sq. miles (12.173136 sq. km)
   FIPS code:            43144
   Located within:       Texas (TX), FIPS 48
   Location:             30.750953 N, 98.680038 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Llano, TX
    Llano