Meaning
A decisive test that gives a conclusive answer about the worth, genuineness or quality of a person or thing. Widely used in journalism, business and politics for the make-or-break check that settles the question once and for all. Neutral register; standard in news, sport and business writing for any conclusive check. Regional use: General English.
Origin
The literal acid test was an 18th-century method of assaying gold: because nitric acid dissolves base metals but barely affects gold, a sample rubbed on a touchstone and treated with acid showed whether it was genuine. The Oxford English Dictionary records the term from 1759, in the writing of the chemist Robert Dossie. The Phrase Finder traces the earliest known figurative use to the Columbia Reporter, a Wisconsin newspaper, in November 1845 ('Twenty-four years of service demonstrates his ability to stand the acid test'), and the figurative sense then spread through American and general English. A separate, unrelated echo is Ken Kesey's LSD-fuelled 'Acid Test' parties of 1965-66, a pun on drug slang rather than a development of the idiom.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- a real acid test
- pass the acid test
- the acid test
- the ultimate acid test
Usage Examples
- The televised debate will be the acid test of whether the front-runner can survive hostile questioning.
- Passenger numbers over the summer will provide an acid test for the new ferry route.
- Her restoration work passed the acid test when museum curators mistook the panels for originals.