Believe in legal position, constrained by gutless coroner (8)
I believe the answer is:
consider
'believe' is the definition.
(considering is a kind of believing)
'in legal position constrained by gutless coroner' is the wordplay.
'in legal position' becomes 'onside' (in a legal position in eg football).
'constrained by' is an insertion indicator.
'gutless' says to hollow out the word (remove centre letters).
'coroner' with its middle removed is 'cr'.
'onside' going within 'cr' is 'CONSIDER'.
(Other definitions for consider that I've seen before include "Muse, mull over" , "Reckon, deem" , "Cogitate" , "Think about - judge" , "Deem to be, believe" .)