Most tiny (8)
I believe the answer is:
smallest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most tiny</span>' is the definition.<br/ ><span class="explanation-format__explanation">('small' can be similar in meaning to 'tiny')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for smallest that I've seen before include "Least in size or quantity" , "Tiniest" , "Most diminutive" , "Most dimunitive" , "Most ungenerous" .)