Ring round guests, having missed half the conversation (8)
I believe the answer is:
dialogue
'the conversation' is the definition.
(dialogue is a kind of conversation)
'ring round guests' is the wordplay.
'ring' becomes 'dial' (as in dialling a phone).
'round' becomes 'o' (round can mean a round object).
'guests' becomes 'gue' (I can't explain this - if you can you should believe this answer much more).
'dial'+'o'+'gue'='DIALOGUE'
'having missed half' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for dialogue that I've seen before include "Two-way conversation" , "Lines spoken in films, books etc" , "brought into play perhaps" , "part of play one can't perform" , "Conversation as in a play" .)