field test vs trial run

field test and trial run both are nouns.

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

As nouns, trial run is a hypernym of field test; that is, trial run is a word with a broader meaning than field test:

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

Other hypernyms of field test include test, trial, tryout.

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