Expression of greeting (5)
I believe the answer is:
hello
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">expression of greeting</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for hello that I've seen before include "Welcome" , "Meeting greeting" , "Conventional word of greeting" , "Greeting - celebrity magazine" , "glossy magazine" .)