Social occasion of first lady and gentry essentially (5)
I believe the answer is:
event
'social occasion' is the definition.
(I've seen this before)
'first lady and gentry essentially' is the wordplay.
'first lady' becomes 'eve' (I've seen this before).
'and' says to put letters next to each other.
'essentially' means to look at the middle letters.
The central letters of 'gentry' are 'nt'.
'eve'+'nt'='EVENT'
'of' acts as a link.
(Other definitions for event that I've seen before include "Something taking place" , "celebration?" , "Happening, noteworthy perhaps" , "major incident" , "Something that takes place" .)