Point to a popular, timeless dictate (8)
I believe the answer is:
indicate
'point to' is the definition.
(synonyms)
'a popular timeless dictate' is the wordplay.
'a popular' becomes 'in' ('in' can mean trendy).
'timeless dictate' becomes 'dicate' (I can't justify this - if you can you should believe this answer much more).
'in'+'dicate'='INDICATE'
Can you help me to learn more?
(Other definitions for indicate that I've seen before include "Point out or give some notion of" , "Mark" , "Point out, suggest" , "Point, show, signal" , "(Give a) signal" .)