Means of transport for schools (6)
I believe the answer is:
trains
This clue is a double definition.
'means of transport' is the first definition.
(train is a type of transport)
'schools' is the second definition.
(I know this)
'for' acts as a link.
(Other definitions for trains that I've seen before include "Public transport vehicles with carriages" , "Works out" , "Sets of railway cars" , "Aims; coaches" , "schools" .)