Futile, abandoning ship in Merseyside port (6)
I believe the answer is:
bootle
'merseyside port' is the definition.
'futile abandoning ship' is the wordplay.
'futile' becomes 'bootless' ('bootless' can be a synonym of 'futile').
'abandoning' indicates named letters should be taken away.
'ship' becomes 'ss'.
'bootless' with 'ss' taken away is 'BOOTLE'.
'in' acts as a link.
(Other definitions for bootle that I've seen before include "Liverpool neighbour" , "Port" .)