The leader without a stage turn becomes indiscreet (8)
I believe the answer is:
tactless
'indiscreet' is the definition.
(I've seen this before)
'the leader without' is the wordplay.
'the leader' becomes 'tact' (I can't justify this - if you can you should believe this answer much more).
'without' becomes 'less' (I've seen this in another clue).
'tact'+'less'='TACTLESS'
'a stage turn becomes' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tactless that I've seen before include "Lacking sensitivity in dealing with others" , "Lacking skill in handling delicate situations" , "Lacking sensitivity, saying the wrong things" , "Indiscreet" , "Lacking sensitivity toewards others, blundering" .)