End of school time in America (8)
I believe the answer is:
terminus
'end' is the definition.
(I know that terminus is a type of end)
'school time in america' is the wordplay.
'school time' becomes 'term' (term time).
'america' becomes 'US' (United States).
'term'+'in'+'us'='TERMINUS'
'of' acts as a link.
(Other definitions for terminus that I've seen before include "Limit" , "Final stop" , "boundary marker" , "End of a railway or bus route" , "End - objective" .)