Pop voice hosting jolly TV series (4,4)
'tv series' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'pop voice hosting jolly' is the wordplay.
'pop' becomes 'dad' (synonyms).
'voice' becomes 'say' (I can't justify this - if you can you should give a lot more credence to this answer).
'hosting' is an insertion indicator.
'jolly' becomes 'rm'.
'say' enclosing 'rm' is 'sarmy'.
Can you help me to learn more?
(Other definitions for dads army that I've seen before include "Evergreen TV comedy" , "Show" , "TV programme" , "British sitcom featuring the Home Guard" .)