Second option mostly involving ultimate academic (10)
I believe the answer is:
scholastic
'academic' is the definition.
(I've seen this before)
'second option mostly involving ultimate' is the wordplay.
I cannot really see how this works, but
'second' could be 'tic' (tic or tick can mean a short amount of time) and 'tic' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for scholastic that I've seen before include "Educative" , "Academic" , "Learned" , "Pertaining to teaching and educational establishments" , "Relating to education" .)