A test one gets on with, for progress (6)
I believe the answer is:
motion
'for progress' is the definition.
(thesaurus)
'a test one gets on' is the wordplay.
'a test' becomes 'MOT' (as in an MOT test for a vehicle).
'one' becomes 'i' (Roman numeral).
'gets' is a charade indicator (letters next to each other).
'mot'+'i'+'on'='MOTION'
'with' acts as a link.
(Other definitions for motion that I've seen before include "Formal proposal for debate" , "That's debatable" , "Moving - proposal" , "Proposal to be voted on" , "inducing nausea in some travellers" .)