Piece of evidence solvers are familiar with (4)
I believe the answer is:
clue
This clue could be a double definition.
'piece of evidence' is the first definition.
(I've seen this before)
'solvers are familiar with' is the second definition.
I know that 'solvers' relates to this answer.
Can you help me to learn more?
(Other definitions for clue that I've seen before include "Crossword item" , "Hint; piece of evidence" , "contribution to crossword" , "It helps solve a crime" , "Hint to get what this is?" .)