Popular dénouement must include time and meaning (9)
I believe the answer is:
intending
'meaning' is the definition.
('intend' can be a synonym of 'mean')
'popular denouement must include time' is the wordplay.
'popular' becomes 'in'.
'denouement' becomes 'ending'.
'must include' indicates putting letters inside.
'time' becomes 't'.
'in'+'ending'='inending'
'inending' enclosing 't' is 'INTENDING'.
'and' acts as a link.
(Other definitions for intending that I've seen before include "Meaning; planning" , "Planning, proposing" .)