Preacher throws stone into a bar (7)
I believe the answer is:
apostle
'preacher' is the definition.
(I've seen this before)
'stone into a bar' is the wordplay.
'stone' becomes 'st'.
'into' means one lot of letters goes inside another.
'bar' becomes 'pole' ().
'a'+'pole'='apole'
'st' put inside 'apole' is 'APOSTLE'.
'throws' acts as a link.
This may not be right. It may belong to another bit of the clue.
(Other definitions for apostle that I've seen before include "Good man" , "Leaps to find religious follower" , "A preacher of gospels" , "Preacher perhaps" , "Principal champion" .)