tester vs test

tester and test both are nouns.

Word	Noun	Adjective	Verb	Adverb
tester	Yes	No	No	No
test	Yes	No	Yes	No

tester (noun)	test (noun)
a flat canopy (especially one over a four-poster bed)	the act of testing something
someone who administers a test to determine your qualifications	any standardized procedure for measuring sensitivity or memory or intelligence or aptitude or personality etc
	the act of undergoing testing
	a hard outer covering as of some amoebas and sea urchins
	trying something to find out about it
	a set of questions or exercises evaluating skill or knowledge

tester (verb)	test (verb)
	undergo a test
	examine someone's knowledge of something
	determine the presence or properties of (a substance)
	achieve a certain score or rating on a test
	put to the test, as for its quality, or give experimental use to
	test or examine for the presence of disease or infection
	show a certain characteristic when tested