the acid test

acid test

A conclusive test. The phrase comes from the 19th-century practice of testing metals in nitric acid to determine if they contained gold. Restructuring the organization will be the acid test that determines whether or not it can survive the sudden downturn in the economy.
See also: acid, test
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

the acid test

COMMON If you call something the acid test, it will prove how effective or useful something is. The acid test for the vaccine will be its performance in the south where the disease is more widespread. So far, I don't feel too bad but I'm waiting for my first really stressful day when things go wrong. That will be the real acid test. Note: Nitric acid can be used to test whether a metal is pure gold because it damages most metals but does not affect gold.
See also: acid, test
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012

the acid test

a situation or event which finally proves whether something is good or bad, true or false, etc.
The original use of the phrase was to describe a method of testing for gold with nitric acid (gold being resistant to the effects of nitric acid).
1990 Which? These deals are designed to encourage impulse buying, so the acid test is whether you would have bought anyway.
See also: acid, test
Farlex Partner Idioms Dictionary © Farlex 2017

the ˌacid ˈtest (of something)

(also the ˈlitmus test especially in American English ) a situation which finally proves whether something is good or bad, true or false, etc: They’ve always been good friends, but the acid test will come when they have to share a flat.Both these expressions originally referred to chemical tests. The acid test uses nitric acid to test if something is made of gold. The litmus test uses litmus paper to test for acids and alkalis.
See also: acid, test
Farlex Partner Idioms Dictionary © Farlex 2017

acid test, the

A conclusive trial to establish the truth or worth of something or someone. The term comes from a test long used to distinguish gold from copper or some other metal. Most corrosive acids do not affect gold, but a solution of nitric acid and hydrochloric acid dissolves the metal. Used literally by jewelers in the late nineteenth century, the term soon was employed figuratively, by U.S. president Woodrow Wilson among others.
See also: acid
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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References in periodicals archive ?
The club's feeling is that it's been far too long since we've won the league, and that's what I see as the acid test. My goal is to try to put a team in place over the next three years that will allow us to do that.
But we gave Kia the acid test of just how far they have come for quality and perception of class with a special "Daz challenge".
HUNTER'S VERDICT This is the acid test for Sunderland's players.
"I have no doubt in my mind the acid test is tomorrow."
He has been impressive in winning both his races so far and this is the acid test."
Pass the acid test with flying colours WHAT 9 soil conditions will my hydrangeas prefer?
Now Shilton believes the Spaniard is facing the acid test of his Old Trafford revival as Fergie's men travel to the Etihad Stadium for the biggest derby in history.
I've not seen or studied these latest figures in detail yet but migration of working age people is the acid test in the real world.
IF Big Country are about to take the acid test, expect them to be officially verified as pure gold.
WOLVES 1 Fletcher (88) NEWCASTLE 2 Ba (17), Gutierrez (38) NEWCASTLE manager Alan Pardew believes his side's next match will provide the acid test for what can be achieved at St James' Park this season.
Rana Sanaullah said whatever MQM says represents its own perspective, adding the acid test will be the number of votes cast in its favour.
"The problem now is how we progress as a team, in a different way to when he was here." And Fergie believes facing newly-promoted Birmingham will be the acid test of whether or not the club was right to spend pre-season in the Far East as well as playing a mini-tournament in Munich.
LEICESTER acting coach Richard Cockerill described next Saturday's Heineken Cup Pool Three decider against the Ospreys at the Liberty Stadium as "the acid test" for his side after crushing Treviso at Welford Road.
However, the acid test will come in Belfast against unfancied Northern Ireland, who will overtake them should they achieve a victory in front of their own fans.
Pam Lee, regional director for Business in the Community, said: "Through sessions such as the Acid Test, companies can learn at first hand how they can reap the wide-ranging benefits of being a responsible employer who understands the needs of the community, be that regionally, nationally or internationally."