A long time and varied things to be done (6)
I believe the answer is:
agenda
'things to be done' is the definition.
(I've seen this in another clue)
'a long time and varied' is the wordplay.
'a long time' becomes 'age' (an age is a period of time).
'varied' indicates an anagram.
'and' is an anagram of 'nda'.
'age'+'nda'='AGENDA'
(Other definitions for agenda that I've seen before include "matters for discussion" , "Meeting's topics" , "List of things to be done or discussed" , "plan of things to be done" , "Table of business" .)