Detective reveals earl's lost article in jar (8)
I believe the answer is:
sherlock
'detective' is the definition.
(I know that sherlock is a type of detective)
'earl's lost article in jar' is the wordplay.
'lost' is a deletion indicator.
'article' becomes 'a' (the indefinite article in English).
'in' means one lot of letters goes inside another.
'jar' becomes 'shock' (I've seen this before).
'earl' with 'a' taken away is 'erl'.
'erl' placed within 'shock' is 'SHERLOCK'.
'reveals' is the link.
(Other definitions for sherlock that I've seen before include "Fictional detective" , "Arthur Conan Doyle's detective" , "Conan Doyle's sleuth, . . . . . . . . Holmes" , "Fictional sleuth . . . . . . . . Holmes" , "Mr Holmes" .)