Attempt to comprehend elderly affliction (7)
I believe the answer is:
tragedy
'affliction' is the definition.
(both can mean a terrible situation)
'attempt to comprehend elderly' is the wordplay.
'attempt' becomes 'try' (synonyms).
'to comprehend' means one lot of letters goes inside another (comprehend can mean to contain or include).
'elderly' becomes 'aged' (synonyms).
'try' going around 'aged' is 'TRAGEDY'.
(Other definitions for tragedy that I've seen before include "Huge blow" , "Calamity as in sad play" , "story ending unhappily" , "sad event" , "King Lear, perhaps" .)