Monthly article on old people (4)
I believe the answer is:
maya
'old people' is the definition.
(I've seen this before)
'monthly article on' is the wordplay.
'monthly' becomes 'may' (I can't explain this - if you can you should give a lot more credence to this answer).
'article' becomes 'a' (English indefinite article).
'on' says to put letters next to each other.
'may'+'a'='MAYA'
Can you help me to learn more?
(Other definitions for maya that I've seen before include "Indian" , "Central American language" , "Member of a native American family living in Mexico until the 15th century" , "The illusory world" , "People of the New World" .)