Stony (4)
'stony' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for hard that I've seen before include "Solid, firm, rigid" , "to be listened to in Scotland" , "Firm, rigid, road leading to foreshore" , "Solid; difficult" , "Tough - difficult" .)
'stony' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for pebbly that I've seen before include "beach?" , "Covered in small stones" .)
'stony' is the definition.
(I know that stony can be written as flinty)
This is the entire clue.
(Another definition for flinty that I've seen is " Hard and unyielding".)