Implied, understood (5)
I believe the answer is:
tacit
This clue is a double definition.
'implied' is the first definition.
(synonyms)
'understood' is the second definition.
(I know that understood can be written as tacit)
(Other definitions for tacit that I've seen before include "Silent - understood" , "Implied but not directly expressed" , "Attic? (anag)" , "Silently understood" , "Understood, implicit" .)