Definitions
a basis for comparison; a reference point against which other things can be evaluated
Word origin
From touch + stone.
Used in a sentence
“Near-synonym: comparator”
“The foregoing doctrine affords us also a touchstone for the trial of spirits.”
“"Expectation of life" is an elastic term: the touchstone here is rather the aggregate amount of work that the locomotive does during its working life.”
Source: Wiktionary, CC BY-SA 4.0
Used as a crossword answer1 curated clues
01“Standard for comparison”10 letters
Not quite right?
"Search similar patterns."
T_________