Formal meeting to lay to rest opinion (9)
I believe the answer is:
interview
'formal meeting' is the definition.
(I've seen this before)
'lay to rest opinion' is the wordplay.
'lay to rest' becomes 'inter' (synonyms).
'opinion' becomes 'view' (synonyms).
'inter'+'view'='INTERVIEW'
'to' acts as a link.
(Other definitions for interview that I've seen before include "to ask questions" , "job talk" , "official meeting" , "format for talk show" , "encounter" .)