Many increases in times of trouble (6)
I believe the answer is:
crises
'times of trouble' is the definition.
(I've seen this in another clue)
'many increases' is the wordplay.
'many' becomes 'c' (C is the Roman numeral for 100).
'increases' becomes 'rises' (rise is a kind of increase).
'c'+'rises'='CRISES'
'in' is the link.
(Other definitions for crises that I've seen before include "serious problems" , "lot of emergencies" , "difficult moments" , "Moments of panic" , "desperate situations" .)