Learn about modern times (4)
I believe the answer is:
read
'learn' is the definition.
('read' can be a synonym of 'learn')
'about modern times' is the wordplay.
'about' becomes 're' (regarding).
'modern times' becomes 'ad' (I've seen this in other clues).
're'+'ad'='READ'
(Other definitions for read that I've seen before include "Interpret (text)" , "Study (for a degree?)" , "Con" , "Interpret printed matter" , "examined" .)