Where some journalists work briefly, then (2,3,4)
I believe the answer is:
at the time
'then' is the definition.
(synonyms)
'where some journalists work briefly' is the wordplay.
'where some journalists work' becomes 'at the Times' (London or NY Times newspaper).
'briefly' means to remove the last letter.
'atthetimes' with its final letter taken away is 'AT THE TIME'.
(Other definitions for at the time that I've seen before include "In that period" , "In those days" .)