The endless noise made by the cast (5)
I believe the answer is:
throw
'the cast' is the definition.
(I've seen this before)
'the endless noise made by' is the wordplay.
'endless' means to remove the last letter.
'noise' becomes 'row'.
'made by' says to put letters next to each other (letters written or made by another set of letters).
'the' with its final letter taken off is 'th'.
'th'+'row'='THROW'
(Other definitions for throw that I've seen before include "Toss" , "Sling" , "puzzle" , "Form (pot) on a wheel" , "put on floor" .)