Just open (4)
I believe the answer is:
ajar
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">just open</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ajar that I've seen before include "letting in a little light?" , "Open by a chink" , "Not quite closed" , "(Of door) slightly open" , "Barely open" .)