Ship, rather infested with cockroach, cleaned out (8)
I believe the answer is:
schooner
'ship' is the definition.
(I've seen this before)
'rather infested with cockroach cleaned out' is the wordplay.
'rather' becomes 'sooner' (I've seen this in other clues).
'infested with' is an insertion indicator.
'cleaned out' means to remove the middle letters.
'cockroach' with its centre taken out is 'ch'.
'sooner' placed around 'ch' is 'SCHOONER'.
(Other definitions for schooner that I've seen before include "A measure or glass for sherry" , "Old sailing ship and tall sherry glass" , "No chores on this sailing ship" , "Swift sailing vessel - sherry glass" , "Sailing vessel used in former times" .)