Grave, perhaps, that may reveal one's origins (6)
I believe the answer is:
accent
This clue is a double definition.
'grave perhaps' is the first definition.
(grave accent is a type of accent mark)
'that may reveal one's origins' is the second definition.
(an accent might reveal where someone is from)
(Other definitions for accent that I've seen before include "Emphasis; mark on a letter" , "A diacritic mark" , "It could be acute" , "eg Acute" , "Stress - regional dialect" .)