Look-alike may be dead (6)
I believe the answer is:
ringer
'look-alike' is the definition.
(I know that ringer is a type of look-alike)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ringer that I've seen before include "Lookalike" , "American impostor" , "Campanologist - if dead, double" , "One making the toll" , "someone who shouldn't be competing?" .)