Trouble or afflict (3)
I believe the answer is:
ail
I believe this clue is a double definition.
'trouble' is the first definition.
(synonyms)
'afflict' is the second definition.
(synonyms)
(Other definitions for ail that I've seen before include "Afflict -- feel unwell" , "Become sick" , "Be unwell, feel poorly" , "pain" , "Sicken" .)