noun touch·stone \ˈtəch-ˌstōn\

Definition of touchstone

  1. 1 :  a black siliceous stone related to flint and formerly used to test the purity of gold and silver by the streak left on the stone when rubbed by the metal

  2. 2 :  a test or criterion for determining the quality or genuineness of a thing

  3. 3 :  a fundamental or quintessential part or feature :  basis a touchstone film of that decade now considered a touchstone of the city's life — Michael Specter

touchstone was our Word of the Day on 12/14/2008. Hear the podcast!

Examples of touchstone in a sentence

  1. Good service is one touchstone of a first-class restaurant.

  2. his book has long been a touchstone for travel writing that aspires to be literature

Did You Know?

Our example sentence uses "touchstone" in its most recently acquired sense: "a fundamental part." The earlier sense, "a criterion for quality" (as in "I Love Lucy is often seen as a touchstone for comparison with today's TV comedy shows"), provides a better clue to the original meaning of "touchstone," however. The "criterion" sense, which goes back more than 470 years, alludes to a method of testing the purity of a sample of gold. The sample was rubbed on a piece of dark quartz or jasper - the "touchstone." The mark it made was compared to adjacent rubbings on the touchstone from gold of known purity. This method has proved accurate enough that touchstones are still used by jewelers today.


First Known Use of touchstone


Synonym Discussion of touchstone

standard, criterion, gauge, yardstick, touchstone mean a means of determining what a thing should be. standard applies to any definite rule, principle, or measure established by authority standards of behavior. criterion may apply to anything used as a test of quality whether formulated as a rule or principle or not questioned the critic's criteria for excellence. gauge applies to a means of testing a particular dimension (as thickness, depth, diameter) or figuratively a particular quality or aspect polls as a gauge of voter dissatisfaction. yardstick is an informal substitute for criterion that suggests quantity more often than quality housing construction as a yardstick of economic growth. touchstone suggests a simple test of the authenticity or value of something intangible fine service is one touchstone of a first-class restaurant.

Other Mining and Drilling Terms

TOUCHSTONE Defined for English Language Learners


noun touch·stone \ˈtəch-ˌstōn\

Definition of touchstone for English Language Learners

  • : something that is used to make judgments about the quality of other things

Seen and Heard

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capable of being understood in two ways

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