Fantasy hulk, a gorgeous guy! (9)
I believe the answer is:
dreamboat
'a gorgeous guy' is the definition.
The definition suggests a singular noun which matches the answer.
'fantasy hulk' is the wordplay.
'fantasy' becomes 'dream' (dream is a kind of fantasy).
'hulk' becomes 'boat' (I am not sure about this - if you are sure you should believe this answer much more).
'dream'+'boat'='DREAMBOAT'
Can you help me to learn more?
(Other definitions for dreamboat that I've seen before include "highly desirable figure?" , "Hunk" , "Very attractive man" , "Dishy fellow" , "Stunner (for drifting off in?)" .)