Enthusiastic about new beginning of partnership, after this? (3,5)
I believe the answer is:
hen party
'this?' is the definition.
The definition suggests a singular noun which matches the answer.
'enthusiastic about new beginning of partnership' is the wordplay.
'enthusiastic' becomes 'hearty' (I've seen this before).
'about' is an insertion indicator.
'new' becomes 'n'.
'beginning of' suggests taking the first letters.
The initial letter of 'partnership' is 'p'.
'n'+'p'='np'
'hearty' enclosing 'np' is 'HEN-PARTY'.
'after' is the link.
(Other definitions for hen party that I've seen before include "Women's social gathering" , "Women's gathering (colloq.)" , "One last night of debauchery" , "pre-wedding bash" , "Event to which stags are not invited" .)