Lead a request for silence on the meadow (5)
I believe the answer is:
leash
'lead' is the definition.
(I know that lead can be written as leash)
'a request for silence on the meadow' is the wordplay.
'a request for silence' becomes 'sh' ('sh' is used to tell someone to be quiet).
'on' says to put letters next to each other.
'the meadow' becomes 'lea' (a lea is a grassy area).
'sh' after 'lea' is 'LEASH'.
(Other definitions for leash that I've seen before include "Three animals" , "Line for controlling a dog" , "Strap for holding a dog while walking" , "(Dog's) lead" , "Restraint for a dog" .)