Improve a lecture about male priest (10)
I believe the answer is:
ameliorate
'improve' is the definition.
(synonyms)
'a lecture about male priest' is the wordplay.
'a lecture' becomes 'orate' (I've seen this before).
'about' means one lot of letters go next to another.
'male' becomes 'am' (I can't explain this - if you can you should believe this answer much more).
'priest' becomes 'eli' (biblical figure).
'am'+'eli'='ameli'
'orate' after 'ameli' is 'AMELIORATE'.
Can you help me to learn more?
(Other definitions for ameliorate that I've seen before include "Make (something) better" , "seen to improve" , "Become better" , "Make (a bad thing) better" .)