trial run vs field test

trial run and field test both are nouns.

Word	Noun	Adjective	Verb	Adverb
trial run	Yes	No	No	No
field test	Yes	No	No	No

As nouns, field test is a hyponym of trial run; that is, field test is a word with a more specific, narrower meaning than trial run:

trial run: trying something to find out about it
field test: a test of the performance of some new product under the conditions in which it will be used

Other hyponyms of trial run include field trial, alpha test, beta test, road test, trial balloon.

trial run (noun)	field test (noun)
trying something to find out about it	a test of the performance of some new product under the conditions in which it will be used