Ark struggling with no more sail (9)
I believe the answer is:
moonraker
'sail' is the definition.
(type of sail)
'ark struggling with no more' is the wordplay.
'struggling with' indicates anagramming the letters (the letters struggle or wriggle into a new form).
'no'+'more'='nomore'
'ark' anagrammed with 'nomore' makes 'MOONRAKER'.
(Other definitions for moonraker that I've seen before include "James Bond film" , "Book" , "Wiltshireman" , "James bond novel" , "Small square sail" .)