Shock maybe about old books offering nonsense (3,3)
I believe the answer is:
hot air
'nonsense' is the definition.
(hot air is a kind of nonsense)
'shock maybe about old books' is the wordplay.
'shock maybe' becomes 'hair' (shock can mean a mass of hair).
'about' is an insertion indicator.
'old books' becomes 'ot' (Old Testament).
'hair' enclosing 'ot' is 'HOT-AIR'.
'offering' is the link.
(Other definitions for hot air that I've seen before include "Empty or boastful talk - good for balloons" , "Bombast or balloon filler" , "Bluster" , "Guff" , "Empty bombast often found in balloon" .)