In school, used to be provided with juice (7)
I believe the answer is:
powered
'provided with juice' is the definition.
I can't tell whether this definition defines the answer.
'in school used to be' is the wordplay.
'in' means one lot of letters goes inside another.
'school' becomes 'pod' (I've seen this before).
'used to be' becomes 'were' (I've seen this before).
'pod' enclosing 'were' is 'POWERED'.
Can you help me to learn more?
(Other definitions for powered that I've seen before include "Supplied with energy" , "Wee drop (anag.)" , "fed juice" , "Like anything with an engine" , "Supplied the force to function" .)