Laurel traps a devil (5)
I believe the answer is:
satan
'devil' is the definition.
(I know that devil can be written as Satan)
'laurel traps a' is the wordplay.
'laurel' becomes 'stan' (comedian Stan Laurel is an example).
'traps' is an insertion indicator.
'stan' going around 'a' is 'SATAN'.
(Other definitions for satan that I've seen before include "Fiend" , "Diabolical figure" , "Prince of Darkness" , "Fallen archangel" , "The devil, Beelzebub" .)