Temporarily debar second writer in French south (7)
I believe the answer is:
suspend
'temporarily debar' is the definition.
(I've seen this before)
'second writer in french south' is the wordplay.
'second' becomes 's' (common abbreviation).
'writer' becomes 'pen' (something which writes).
'in' means one lot of letters goes inside another.
'french south' becomes 'sud' ('south' in French).
's'+'pen'='spen'
'spen' going inside 'sud' is 'SUSPEND'.
(Other definitions for suspend that I've seen before include "Remove temporarily from office - hang" , "Keep in abeyance" , "Hang, defer" , "Stay" , "Fail to hit" .)