PM briefly appearing in school to give talk (6)
I believe the answer is:
speech
'talk' is the definition.
(I've seen this before)
'pm briefly appearing in school' is the wordplay.
'pm briefly' becomes 'pee' (I can't explain this - if you can you should believe this answer much more).
'appearing in' means one lot of letters goes inside another.
'school' becomes 'sch'.
'pee' placed within 'sch' is 'SPEECH'.
'to give' acts as a link.
Can you help me to learn more?
(Other definitions for speech that I've seen before include "Giving address" , "Oral form of communication" , "Oration to an audience" , "Speaking faculty" , "Talking - language - oration" .)