Bottle – neck (5)
I believe the answer is:
nerve
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">bottle</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(both can mean courage)</span><br/ ><br/ >'<span class="explanation-format__original">neck</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(both can mean attitude or insolence)</span><br/ ><br/ ></span>
(Other definitions for nerve that I've seen before include "Cheek; self-possession" , "Cool courage" , "Cord that carries instructions from brain to body" , "Bottle, courage" , "Strand of body fibre" .)