Clergyman, one sat in church seat for the early show? (7)
I believe the answer is:
preview
'the early show?' is the definition.
(I've seen this before)
'clergyman one sat in church seat' is the wordplay.
'clergyman' becomes 'rev' (short for reverend).
'one sat' becomes 'i' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'church seat' becomes 'pew' (I've seen this before).
'rev'+'i'='revi'
'revi' going inside 'pew' is 'PREVIEW'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for preview that I've seen before include "An advance look" , "See ahead" , "Preliminary showing" , "Advance showing before general release" , "early show" .)