Giggle about women's social network (7)
I believe the answer is:
'social network' is the definition.
'giggle about women's' is the wordplay.
'giggle' becomes 'titter' (synonyms).
'about' means one lot of letters goes inside another.
'women' becomes 'w' (standard abbreviation).
'titter' going around 'w' is 'TWITTER'.
(Other definitions for twitter that I've seen before include "e-fad" , "Bird's sound; trivial talk" , "flutter" , "Chirpy social website" , "Chirpy social medium" .)