Frequently one is sad without a newspaper (5)
I believe the answer is:
often
'frequently' is the definition.
(synonyms)
'one is sad without a newspaper' is the wordplay.
'is sad' indicates an anagram.
'without' indicates putting letters inside ('without' can be similar in meaning to 'outside').
'a newspaper' becomes 'FT' (Financial Times newspaper).
'one' is an anagram of 'oen'.
'oen' going around 'ft' is 'OFTEN'.
(Other definitions for often that I've seen before include "Much of the time" , "on numerous occasions" , "Repeatedly, many times" , "Frequently, not seldom" , "Frequently, many times" .)