Ancient Head of Entertainment dividing a TV channel (3-3)
I believe the answer is:
age-old
'ancient' is the definition.
(I've seen this before)
'head of entertainment dividing a tv channel' is the wordplay.
'head of' indicates taking the first letters.
'dividing' means one lot of letters goes inside another (inserted letters divide the word).
'tv channel' becomes 'gold' (I can't justify this - if you can you should believe this answer much more).
The initial letter of 'entertainment' is 'e'.
'a'+'gold'='agold'
'e' placed into 'agold' is 'AGE-OLD'.
Can you help me to learn more?
(Other definitions for age-old that I've seen before include "Lasting from times long ago" , "Hallowed by antiquity" , "Extremely ancient" , "Having been around for many years" , "Having existed for a very long time" .)