Topical recent letters (5)
I believe the answer is:
newsy
'topical' is the definition.
Both the answer and definition are adjectives. Perhaps you can see an association between them that I can't see?
'recent letters' is the wordplay.
'recent' becomes 'new' (similar in meaning).
'letters' becomes 'sy' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'new'+'sy'='NEWSY'
Can you help me to learn more?
(Other definitions for newsy that I've seen before include "Gossip-laden" , "Full of intelligence" , "Full of up-to-date information" , "like gossip column?" , "Gossipy" .)