Bit of a thin time, I suggest (4)
I believe the answer is:
hint
'suggest' is the definition.
(synonyms)
'bit of a thin time i' is the wordplay.
'bit of' indicates the answer is hidden within the clue.
'HINT' is hidden within 'thin time i'.
(Other definitions for hint that I've seen before include "Indirect clue" , "Small trace; clue" , "Tip - small amount" , "Helpful suggestion" , "CRT screen coating" .)