Checks a devious siren (5)
I believe the answer is:
reins
'checks' is the definition.
(reining is a kind of checking)
'a devious siren' is the wordplay.
'a devious' indicates an anagram.
'siren' is an anagram of 'REINS'.
(Other definitions for reins that I've seen before include "water regulators?" , "Rider's straps" , "Harnesses" , "Bridle straps" , "They're used to control" .)