touchstone

• POS: Noun
• HYPHEN: touch=stone

CIDE DICTIONARY

touchstone, n. 

•  Lydian stone; basanite; -- so called because used to test the purity of gold and silver by the streak which is left upon the stone when it is rubbed by the metal. See Basanite.  [1913 Webster]
•  Any test or criterion by which the qualities of a thing are tried.  Hooker.  [1913 Webster]

  "The foregoing doctrine affords us also a touchstone for the trial of spirits."  [1913 Webster]

Irish touchstone (Min.), basalt, the stone which composes the Giant's Causeway.

OXFORD DICTIONARY

touchstone, n.
1 a fine-grained dark schist or jasper used for testing alloys of gold etc. by marking it with them and observing the colour of the mark.
2 a standard or criterion.

THESAURUS

touchstone

acid test, assay, barometer, benchmark, blank determination, brouillon, canon, check, criterion, crucial test, crucible, degree, demonstration, determination, docimasy, essay, feeling out, first draft, gauge, graduated scale, kiteflying, measure, model, norm, ordeal, parameter, pattern, probation, proof, quantity, reading, readout, reference, rough draft, rough sketch, rule, scale, sounding out, standard, test, test case, trial, try, type, value, verification, yardstick

ROGET THESAURUS

touchstone

Experiment

N experiment, essay, analysis, screen, trial, tentative method, t=atonnement, verification, probation, experimentum crucis, proof, (demonstration), criterion, diagnostic, test, probe, crucial test, acid test, litmus test, crucible, reagent, check, touchstone, pix, assay, ordeal, ring, litmus paper, curcuma paper, turmeric paper, test tube, analytical instruments, empiricism, rule of thumb, feeler, trial balloon, pilot balloon, messenger balloon, pilot engine, scout, straw to show the wind, speculation, random shot, leap in the dark, analyzer, analyst, assayist, adventurer, experimenter, experimentist, experimentalist, scientist, engineer, technician, subject, experimentee, guinea pig, experimental animal, protocol, experimental method, blind experiment, double-blind experiment, controlled experiment, poll, survey, opinion poll, epidemiological survey, retrospective analysis, retrospective survey, prospective survey, prospective analysis, statistical analysis, literature search, library research, tryout, audition, discovery, measurement, evidence, deduction, induction, abduction, experimental, empirical, probative, probatory, probationary, provisional, analytic, docimastic, tentative, unverified, unproven, speculative, untested, on trial, under examination, on probation, under probation, on one's trial, on approval, check it out, give it a try, see how it goes, Run it up the flagpole and see who salutes.