zhào​yāo​jìng

litmus test

照妖镜 (照妖鏡) zhào​yāo​jìng
litmus test noun
a figurative means of exposing the truth, uncovering a conspiracy, or revealing someone's true character
magic mirror noun
a mythical mirror used in folklore to reveal the true form of demons or monsters

Frequency

Movie subtitles
0.060 per million appears in 0% of films
Written text
0.215 per million

Sources

Definitions
CC-CEDICT