Start school (9)
I believe the answer is:
institute
'school?' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for institute that I've seen before include "Organisation for promotion of scientific or educational activity" , "Establish, educational organisation" , "college" , "order as before" , "asylum, possibly?" .)