Acid test

Meaning

A critical trial that proves the value or worth of something.

Usage

Used when describing a decisive, revealing test.

Origin & History

Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.

Chemical reference to acid dissolving fake from real metals.

Adopted into business and technology after chemists used harsh acids to separate metals.