Talk at simple watering hole (9)
I believe the answer is:
speakeasy
'watering hole' is the definition.
(I've seen this before)
'talk at simple' is the wordplay.
'talk' becomes 'speak' (synonyms).
'at' says to put letters next to each other.
'simple' becomes 'easy' (similar in meaning).
'speak'+'easy'='SPEAKEASY'
(Other definitions for speakeasy that I've seen before include "Illicit drinking club (US)" , "Illicit club during Prohibition" , "Illicit bar during Prohibition" , "Dive" , "Prohibition watering hole" .)