Player with instrument nailing finale for President Bush (10)
I believe the answer is:
blackthorn
'bush' is the definition.
(I know that blackthorn is a type of bush)
'player with instrument nailing finale for president' is the wordplay.
'player with' becomes 'black' (I can't explain this - if you can you should believe this answer much more).
'instrument' becomes 'horn' (horn is a kind of instrument).
'nailing' indicates putting letters inside.
'finale for' suggests the final letters.
The last letter of 'president' is 't'.
'black'+'horn'='blackhorn'
'blackhorn' placed around 't' is 'BLACKTHORN'.
Can you help me to learn more?
(Other definitions for blackthorn that I've seen before include "A prickly thing" , "Tree producing sloes" , "Sloe-bearing shrub" , "Sloe bush" , "Tree bearing sloes" .)