Formally approve (6)
I believe the answer is:
ratify
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">formally approve</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 ratify that I've seen before include "Give formal approval to" , "Fit ray (anag.)" , "Authorise" , "Approve officially" , "Confirm or accept, say a treaty" .)