Goodbye and good luck (8)
I believe the answer is:
farewell
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">goodbye and good luck</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for farewell that I've seen before include "Parting word" , "symphony" , "Say goodbye" , "Goodbye, cheerio" , "It may be said when 15" .)