College taking Greek holiday material (8)
I believe the answer is:
concrete
'material' is the definition.
(thesaurus)
'college taking greek holiday' is the wordplay.
'college' becomes 'c'.
'taking' becomes 'on' (eg one taking drugs is 'on' drugs).
'greek holiday' becomes 'crete' (I can't justify this - if you can you should believe this answer much more).
'c'+'on'+'crete'='CONCRETE'
Can you help me to learn more?
(Other definitions for concrete that I've seen before include "Specific; definite" , "Specific - building material" , "Not abstract - construction material" , "that may be reinforced" , "Definite; building material" .)