The board in charge of movements in the main (9)
I believe the answer is:
admiralty
This clue could be a double definition.
'the board' is the first definition.
The answer and definition can be both groups as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'charge of movements in the main' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'in' acts as a link.
Can you help me to learn more?
(Other definitions for admiralty that I've seen before include "Department of 1 across in charge of the Navy" , "HQ" , "UK state department in charge of the Royal Navy" , "Former Department in charge of the navy in Britain" .)