Proceed (2,5)
(Other definitions for go ahead that I've seen before include "Pioneering (green light?)" , "Permission to proceed" , "Signal to proceed" , "Lead" , "Up-and-coming -- authorisation" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">proceed</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for continue that I've seen before include "Last" , "Persist" , "Proceed" , "Carry on" , "Don't stop, keep going" .)