Nomadic captain left upset by real estate website (6)
I believe the answer is:
domain
'nomadic captain left' is the definition.
The answer and definition can be both groups as well as being singular nouns.
Maybe they are linked in a way I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for domain that I've seen before include "Scope of knowledge - owned land" , "Area under someone's control, field of activity" , "Range of influence or field of thought" , "Territory over which someone reigns" , "Territory over which rule or control is exercised" .)