Hear about ancient disaster (7)
I believe the answer is:
tragedy
'disaster' is the definition.
('tragedy' can be a synonym of 'disaster')
'hear about ancient' is the wordplay.
'hear' becomes 'try' ('try' can be a synonym of 'hear').
'about' is an insertion indicator.
'ancient' becomes 'aged' (I've seen this before).
'try' going around 'aged' is 'TRAGEDY'.
(Other definitions for tragedy that I've seen before include "Sad story" , "sad event" , "Huge blow" , "Drama genre" , "Sophoclean drama" .)