Between open and closed (4)
I believe the answer is:
ajar
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">between open and closed</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 "A little bit open, like door" , "partly opened" , "Half open" , "not entirely open" , "Half-open" .)