Nod (2-5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">nod</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for go-ahead that I've seen before include "Pioneering (green light?)" , "Enterprisingly progressive" , "Permission to proceed" , "Up-and-coming - authorisation" , "Enterprising" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">nod</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for bow that I've seen before include "Bend from the waist in deference" , "at front of vessel" , "Front of boat" , "Arc" , "Bending in reverence or shame" .)