Dickens' times were this tough! (4)
I believe the answer is:
hard
'this tough' is the definition.
(I've seen this in another clue)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for hard that I've seen before include "Solid, firm, rigid" , "Firm, rigid, road leading to foreshore" , "Intensely" , "Novel featuring Mr Gradgrind" , "to be listened to in Scotland" .)