Unearth very little evidence (5)
I believe the answer is:
trace
I believe this is a triple definition!
'unearth' is the first definition.
(thesaurus)
'very little' is the second definition.
(I've seen this before)
'evidence' is the third definition.
(trace is a kind of evidence)
(Other definitions for trace that I've seen before include "Follow step by step" , "a little bit" , "Scarcely detectable amount" , "Minute quantity" , "Track down or make copy" .)