Lofty structure in Felixstowe razed (5)
I believe the answer is:
tower
'lofty structure' is the definition.
(I know this)
'in felixstowe razed' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TOWER' is hidden within 'felixstowe razed'.
(Other definitions for tower that I've seen before include "famous prison" , "tugboat" , "Campanile, for example" , "tractor, perhaps" , "Monument" .)