Milky (7)
I believe the answer is:
lacteal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">milky</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 lacteal that I've seen before include "Milk-like; pertaining to milk" , "Milky resin" .)