litmus test (test for acidity or alkalinity of a substance) · litmus test (any binary test to decisively determine the functonality or applicability of a solution or system)
çekim: çoğul Lackmustests · tamlayan Lackmustests
eş: Prüfstein
köken: Lackmus + Test. In the figurative sense since the 1940s at least, possibly following English usage.