Progress (7)
'progress' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for develop that I've seen before include "Become larger or more mature" , "Unfold" , "'Grow, evolve (7)'" , "Convert (land) to new purpose" , "Result" .)
'progress' is the definition.
(headway is a kind of progress)
This is all the clue.
(Other definitions for headway that I've seen before include "Advance" , "make progress" , "Progress or forward motion" , "Progress or success in work" , "Ground" .)
'progress' is the definition.
(synonyms)
This is all the clue.
(Other definitions for advance that I've seen before include "Put forward (a theory)" , "Early" , "Suggest" , "capital" , "Proceed" .)
'progress' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for inroads that I've seen before include "raid" , "large quantities consumed when these are made" , "Hostile incursions" , "Making them is reductive" , "Major acts of encroachment" .)