Strength needed in order to copy out ten (7)
I believe the answer is:
potency
'strength' is the definition.
(I know that strength can be written as potency)
'order to copy out ten' is the wordplay.
'order to' is an anagram indicator (a different order to the letters).
'out' is an insertion indicator.
'copy' anagrammed gives 'pocy'.
'pocy' enclosing 'ten' is 'POTENCY'.
'needed in' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for potency that I've seen before include "Great power" , "authority" , "Strength - effectiveness" , "Might" , "Capacity" .)