Summon Bishop and judge to depose King (6)
I believe the answer is:
beckon
'summon' is the definition.
(I know that beckon is a more specific form of the action summon)
'bishop and judge to depose king' is the wordplay.
I cannot really see how this works, but
'bishop' could be 'b' (abbreviation for bishop in chess) and 'b' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
'king' could be 'k' (abbreviation for king in chess) and 'k' is present in the answer.
The remaining letters 'eco' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for beckon that I've seen before include "Summon by gesturing" , "Summon with a wave" , "Summon with raised finger" , "Make signs to summon" , "Summon with gesture (6)" .)