Retract gear with boat at sea (8)
I believe the answer is:
abrogate
'retract' is the definition.
(thesaurus)
'gear with boat at sea' is the wordplay.
'with' says to put letters next to each other.
'at sea' indicates anagramming the letters.
'gear' after 'boat' is 'boatgear'.
'boatgear' anagrammed gives 'ABROGATE'.
(Other definitions for abrogate that I've seen before include "Formally cancel (an agreement)" , "Do away with" , "End" , "Cancel or repeal, say a law" , "Get rid of" .)