touchstone

Plural: touchstones

Noun

• a basis for comparison; a reference point against which other things can be evaluated
• A stone used to verify the quality of gold alloys by rubbing them in order to leave a visible trace.
• A standard of comparison or evaluation.

Synonyms

criterion, measure, standard

Related Words

bellwether, benchmark, capstone, cornerstone, exemplar, keystone, model, norm, standard