In haste, perhaps, one may achieve little progress (4)
I believe the answer is:
step
'progress' is the definition.
(thesaurus)
'in haste perhaps one' is the wordplay.
'in' says the answer is hidden in the clue.
'STEP' is hidden in the letters of 'haste perhaps one'.
'may achieve little' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for step that I've seen before include "Indian garment" , "Abrupt change; pace" , "one stage of flight" , "Pest (anag.)" , "Single pace" .)