Former partner, smooth and articulate (7)
I believe the answer is:
express
'articulate' is the definition.
(I've seen this before)
'former partner smooth' is the wordplay.
'former partner' becomes 'ex' (an ex-partner).
'smooth' becomes 'press' (I've seen this before).
'ex'+'press'='EXPRESS'
'and' acts as a link.
(Other definitions for express that I've seen before include "Fleet" , "air" , "Fast - state - train" , "Intimate - squeeze out" , "Explicit" .)