Monk's bit of the rosary, we hear? (4)
I believe the answer is:
bede
'monk's' is the definition.
(the Venerable Bede, 8th-century monk)
'bit of the rosary we hear?' is the wordplay.
'bit of the rosary' becomes 'bead' (as in rosary beads).
'we hear?' shows a homophone (sound like).
'bead' is a homophone of 'BEDE'.
(Other definitions for bede that I've seen before include "Adam, novel name" , "Early English historian" , "Northumbrian monk and historian, d. 735" , "Ancient English historian" , "He wrote the eighth century Ecclesiastical History of the English Nation" .)