Authenticate (5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">authenticate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that authenticate is a more specific form of attest)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for prove that I've seen before include "Verify" , "Show to be true" , "Demonstrate (truth)" , "Demonstrate to be true" , "Ascertain" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">authenticate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that authenticate is a more specific form of certify)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for certify that I've seen before include "Authorise officially" , "Formally confirm" , "Declare; endorse" .)