Social event with meaning for writer (9)
I believe the answer is:
ballpoint
'for writer' is the definition.
(I've seen this before)
'social event with meaning' is the wordplay.
'social event' becomes 'ball' (I've seen this in other clues).
'with' says to put letters next to each other.
'meaning' becomes 'point' (point is a kind of meaning).
'ball'+'point'='BALLPOINT'
(Other definitions for ballpoint that I've seen before include "Biro" , "Writer" , "Type of pen" .)