In progress (5)
'in progress' is the definition.
(synonyms)
This is all the clue.
(Other definitions for ongoing that I've seen before include "Actually in progress" , "Not yet concluded" , "Still in progress" , "Continuing to exist or progress" , "still in operation" .)
'in progress' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for afoot that I've seen before include "Making progress" , "Stirring" , "Happening" , "In the pipeline" , "Astir" .)