Calm down, maintaining strength completely (3,3,3)
I believe the answer is:
all the way
'completely' is the definition.
(both can mean to the fullest extent)
'calm down maintaining strength' is the wordplay.
I cannot quite understand how this works, but
'strength' could be 'thew' (I've seen this in another clue) and 'thew' is located in the answer.
'calm' could be 'allay' (I've seen this before) and 'allay' is present in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for all the way that I've seen before include "Sinatra sang this" , "Completely" , "Without reservation" , "without limit" , "to the end" .)