Butterfly embarrassed naval officer (3,7)
I believe the answer is:
red admiral
'butterfly' is the definition.
(red admiral is a kind of butterfly)
'embarrassed naval officer' is the wordplay.
'embarrassed' becomes 'red' (someone may blush or go red when embarrassed).
'naval officer' becomes 'admiral' (commander of a naval fleet).
'red'+'admiral'='RED ADMIRAL'
(Other definitions for red admiral that I've seen before include "See butterfly" , "Species of butterfly" , "Common butterfly" , "Russian sailor" , "Vanessa" .)