Chat sociable Theresa is in need of (7)
I believe the answer is:
blether
'chat' is the definition.
(thesaurus)
'sociable theresa is in need of' is the wordplay.
'need of' indicates the answer is hidden within the clue (I've seen 'needs' mean this).
'BLETHER' is hidden within 'sociable theresa in'.
(Other definitions for blether that I've seen before include "gas" , "gossip" , "Yak" , "Idle talk" .)