Making progress, in the main (5,3)
I believe the answer is:
under way
'making progress' is the definition.
'under way' can be an answer for 'progress' (I've seen this before). I am not certain of the 'making' bit.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for under way that I've seen before include "In progress" , "Tunnel" , "In motion (nautical)" , "Might sewer network be" , "Going" .)