Fellow pupil beginning to serve chilled infusion outside hotel (10)
I believe the answer is:
schoolmate
'fellow pupil' is the definition.
(I've seen this before)
'beginning to serve chilled infusion outside hotel' is the wordplay.
'beginning to' indicates taking the first letters.
'chilled' becomes 'cool' (similar in meaning).
'infusion' becomes 'mate' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'outside' is an insertion indicator.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
The first letter of 'serve' is 's'.
'cool'+'mate'='coolmate'
'coolmate' placed around 'h' is 'choolmate'.
's'+'choolmate'='SCHOOLMATE'
Can you help me to learn more?
(Other definitions for schoolmate that I've seen before include "childhood chum" , "Friends Reunited contact" , "Young friend" , "fishwife?" , "Childhood friend" .)