SOS! (4)
I believe the answer is:
help
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sos</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 help that I've seen before include "record by the Beatles" , "Contribute to the success of" , "one by the Beatles" , "Be of service" , "Serve" .)