trial period vs test period

trial period and test period both are nouns.

Word	Noun	Adjective	Verb	Adverb
trial period	Yes	No	No	No
test period	Yes	No	No	No

As nouns, trial period and test period are synonyms defined as:

trial period and test period: a period of time during which someone or something is tested

trial period (noun)	test period (noun)
a period of time during which someone or something is tested	a period of time during which someone or something is tested