testing ground vs laboratory

testing ground and laboratory both are nouns.

Word	Noun	Adjective	Verb	Adverb
testing ground	Yes	No	No	No
laboratory	Yes	No	No	No

As nouns, testing ground and laboratory are synonyms defined as:

testing ground and laboratory: a region resembling a laboratory inasmuch as it offers opportunities for observation and practice and experimentation

testing ground (noun)	laboratory (noun)
a region resembling a laboratory inasmuch as it offers opportunities for observation and practice and experimentation	a workplace for the conduct of scientific research
	a region resembling a laboratory inasmuch as it offers opportunities for observation and practice and experimentation