Model put on slip in panic (6)
I believe the answer is:
terror
'panic' is the definition.
(synonyms)
'model put on slip' is the wordplay.
'model' becomes 'T' (Ford Model T car).
'put on' says to put letters next to each other.
'slip' becomes 'error' (slip can mean an error or mistake).
't'+'error'='TERROR'
'in' is the link.
(Other definitions for terror that I've seen before include "Troublesome child" , "State of extreme fear" , "State of extreme fright" , "Great fear" , "Extreme or intense fear" .)