Ship carrying queen’s flag (8)
I believe the answer is:
streamer
'flag' is the definition.
(I know that streamer is a type of flag)
'ship carrying queen's' is the wordplay.
I cannot quite see how this works, but
'queen' could be 'er' (short for Elizabeth Regina ie Queen Elizabeth) and 'er' is located in the answer.
The remaining letters 'stream' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for streamer that I've seen before include "awful cold?" , "Narrow decorative strip or flag" , "Long decorative ribbon - thin flag" , "Long 23 ac or ribbon" , "Ribbon flowing in the wind" .)