common currency

common currency (countable and uncountable, plural common currencies)

1. (literally) A currency that is common to several countries.
2. A standard of measurement that can be used for comparing disparate things.
   • 2017, Paul Hawkin, Drawdown: The most comprehensive plan ever proposed to reverse global warming, page xiv:

     Based on these factors, scientists can calculate their global warming potential, which makes it possible to have a "common currency" for greenhouse gasses, translating any given gas into its equivalent in carbon dioxide.

3. (figuratively) Common practice; a widespread idea, a commonplace habit.
   • 2011, V. Berridge, M. Gorsky, Environment, Health and History, page 264:

     In global climate-speak, terms like 'scenario', 'impact', 'vulnerability', 'irreversible', 'mitigation', 'adaptation' and 'adaptive capacity' have become common currency, verbal coins sometimes so worn that they almost lose meaning, even though they carry sinister messages about the future of humanity.

• “common currency” (US) / “common currency” (UK) in Macmillan English Dictionary.
• “common currency”, in Collins English Dictionary.
• “common currency”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “common currency” in Longman Dictionary of Contemporary English, Longman.