Not needing to be explained (4-7)
I believe the answer is:
self-evident
'not needing to be explained' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for self-evident that I've seen before include "Not needing to be demonstrated" , "Needing no explanation" , "Not requiring further explanation" , "Not needing to be explained" , "Obvious" .)