Pal may keep Turkish spirit mostly for such a journalist (4-5)

'such a journalist' is the definition.
(type of journalist)

'pal may keep turkish spirit mostly' is the wordplay.
'pal' becomes 'mucker' (my old mucker means my friend).
'may keep' indicates putting letters inside.
'turkish spirit' becomes 'raki' (I've seen this before).
'mostly' means to remove the last letter (most but not all of the word).
'raki' with its final letter removed is 'rak'.
'mucker' enclosing 'rak' is 'MUCK-RAKER'.

'for' acts as a link.