Speculator finds papal decree (4)
I believe the answer is:
bull
This clue is a double definition.
'speculator' is the first definition.
(I've seen this in other clues)
'papal decree' is the second definition.
(I've seen this in another clue)
'finds' is the link.
(Other definitions for bull that I've seen before include "Large quadruped" , "Male elephant, say" , "One charging" , "Papal proclamation" , "Male animal" .)