Bottle part (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bottle part</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for neck that I've seen before include "Isthmus - audacity" , "Part of the body - cheek" , "Narrow part of e.g. isthmus" , "sink" , "Col; impudence" .)