Explained act securing end for Macron? (7)
I believe the answer is:
defined
'explained' is the definition.
(I've seen this in another clue)
'act securing end for macron?' is the wordplay.
'act' becomes 'deed' (deed is a kind of act).
'securing' indicates putting letters inside.
'end for macron?' becomes 'fin' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'deed' placed around 'fin' is 'DEFINED'.
Can you help me to learn more?
(Other definitions for defined that I've seen before include "Gave exact meaning or explained scope" , "Gave the exact meaning of, say a word" .)