Way to hit hard (4)
I believe the answer is:
path
'way' is the definition.
(I know that way can be written as path)
'hit hard' is the wordplay.
'hit' becomes 'pat' (pat can mean to touch or hit).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'pat'+'h'='PATH'
'to' is the link.
(Other definitions for path that I've seen before include "Way for pedestrians" , "Established route" , "Track; direction" , "Course of action; track" , "trail" .)