Implicitly understood (5)
I believe the answer is:
tacit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">implicitly understood</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tacit that I've seen before include "Implicit, unspoken" , "Understood without being put into words" , "Not said though understood" , "Implied -- inferred" , "Aircraft engine casing" .)