Not yet manifest (6)
I believe the answer is:
latent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not yet manifest</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 latent that I've seen before include "Existing but not yet manifest" , "Talent (anag)" , "Hidden, not manifest" , "Hidden but able to be developed" , "'Hidden, undeveloped (6)'" .)