0 the true test of the value of something:
It looks good, but will people buy it? That's the acid test.
1 the proof of the value of something, or the standard that something must meet in order to prove its value:
In 1933, the pressurized airplane passed the acid test when it flew from Chicago to Washington at 22,000 feet above heavy storm clouds.
NOVÉ SLOVÁ
European
May 10, 2021
SLOVO DŇA
Shimmer
the acid test