Make up crap about universal truth (11)
I believe the answer is:
manufacture
'make up' is the definition.
(I know that make up can be written as manufacture)
'crap about universal truth' is the wordplay.
'crap' becomes 'manure' (I've seen this before).
'about' indicates putting letters inside.
'universal' becomes 'U' (film certificate).
'truth' becomes 'fact' (true facts).
'u'+'fact'='ufact'
'manure' enclosing 'ufact' is 'MANUFACTURE'.
(Other definitions for manufacture that I've seen before include "Fabricate" , "Make in large quantities" , "Invent" , "Produce" , "fashion?" .)