Stone-throwers put a listening device in sect on Saturday (9)
I believe the answer is:
catapults
'stone-throwers' is the definition.
I can't judge whether this definition defines the answer.
'a listening device in sect on saturday' is the wordplay.
'listening device' becomes 'tap' (I've seen this in another clue).
'in' indicates putting letters inside.
'sect' becomes 'cult' (I've seen this before).
'on' indicates putting letters inside (as in clothing 'on' a person).
'saturday' becomes 's'.
'tap' placed into 'cult' is 'ctapult'.
'a' going into 'ctapult' is 'catapult'.
'catapult'+'s'='CATAPULTS'
'put' acts as a link.
Can you help me to learn more?
(Another definition for catapults that I've seen is " juvenile weapons".)