Having no significance (11)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">having no significance</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 meaningless that I've seen before include "Empty" , "Without significance" , "Men's angle is (anag) -- nonsensical" , "having no worthwhile quality" , "Futile" .)
(Other definitions for null that I've seen before include "Useless - nothing" , "Immaterial and void" , "Legally void" , "Inoperative" , "Invalid, void" .)