Two-thirds of a dozen (5)
I believe the answer is:
eight
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">two-thirds of a dozen</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eight that I've seen before include "Number etched by a skater?" , "power of two" , "Hit, e.g. (anag.)" , "Have one over the . . . . . to be slightly drunk" , "Pints in gallon" .)