Wordnet 3.0
NOUN (1)
1. 
 a region resembling a laboratory inasmuch as it offers opportunities for observation and practice and experimentation; 
- Example: "the new nation is a testing ground for socioeconomic theories"- Example: "Pakistan is a laboratory for studying the use of American troops to combat terrorism"[syn: testing ground, laboratory]
WordNet (r) 3.0 (2006):
testing ground
    n 1: a region resembling a laboratory inasmuch as it offers
         opportunities for observation and practice and
         experimentation; "the new nation is a testing ground for
         socioeconomic theories"; "Pakistan is a laboratory for
         studying the use of American troops to combat terrorism"
         [syn: testing ground, laboratory]