Male supporting party, controller behind the throne? (8)
I believe the answer is:
ballcock
'controller behind the throne?' is the definition.
I can't judge whether this definition defines the answer.
'male supporting party' is the wordplay.
'male' becomes 'cock' (male chicken).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'party' becomes 'ball' (ball is a kind of party).
'cock' after 'ball' is 'BALLCOCK'.
Can you help me to learn more?
(Other definitions for ballcock that I've seen before include "plumbing item" , "One controls the flow" , "Regulator for convenience" , "Device controlling flow of water into tank" , "Device to check inflow into cistern" .)