After vacation, liftboy chose uniform for school (6)
I believe the answer is:
lyceum
'for school' is the definition.
(lyceum is a kind of school)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for lyceum that I've seen before include "French school or concert-hall" , "Aristotle's teaching place" , "College" , "Garden where Aristotle taught philosophy - London theatre" , "hall" .)