a litmus test

something that shows clearly what someone's opinions or intentions are

Usage notes: Litmus is a substance used in chemical tests because it changes colour.

His views on abortion are effectively a litmus test of his views on women's rights.

Name	Pronounced	Usage
Jaquan	-	African American (Modern)
GaÉTan	-	French
Ainslee	AYNZ-lee	English (Rare)
Chisomo	chee-SO-mo	Southern African, Chewa
Praveena	-	Tamil, Indian, Telugu, Malayalam, Kannada, Marathi
Langston	['læŋstən]