Not concealed in Dover terminal (5)
I believe the answer is:
overt
'not concealed' is the definition.
(I've seen this in another clue)
'in dover terminal' is the wordplay.
'in' indicates a hidden word.
'OVERT' is hidden in the letters of 'dover terminal'.
(Other definitions for overt that I've seen before include "Open and undisguised" , "not disguised" , "Plain to see - manifest" , "Conspicuous" , "Openly displayed" .)