Formerly, formerly (4)
'formerly formerly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for erst that I've seen before include "Rest turned formerly" , "At first; formerly" , "in former times" , "in the past" .)
'formerly formerly' is the definition.
I can't judge whether this defines the answer.
'formerly formerly' is the wordplay.
'formerly' becomes 'afore' (I've seen this before).
'formerly' becomes 'time' (I can't explain this - if you can you should believe this answer much more).
'afore'+'time'='AFORETIME'
Can you help me to learn more?
(Another definition for aforetime that I've seen is " Formerly (archaic)".)