Litmus test(idiom)
A test used to determine someone's true intentions or beliefs.
Hindi meaning:परीक्षा सच्चाई की
Synonyms: Sign, Signal, Indication, Proof, Measure
Example: The president's policy on abortion is regarded as a litmus test of his views on women's rights.
Trick to remember: Litmus paper se litmus test karte hai acid ka. 
