Blackboard accessory (6)
'blackboard accessory' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for chalk that I've seen before include "Soft white rock used for writing on boards etc" , "Opposite of cheese?" , "Calcium carbonate" , "Blackboard writing implement" , "Soft white limestone (as distinct from cheese)" .)
'blackboard accessory' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eraser that I've seen before include "An Indian rubber" , "Rubber for removing marks" , "A student's rubber, or the one who uses it" , "Implement to rub out" , "It could remove" .)