Most furious (8)
I believe the answer is:
angriest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most furious</span>' is the definition.<br/ ><span class="explanation-format__explanation">('angry' can be similar in meaning to 'furious')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for angriest that I've seen before include "Most annoyed or hostile" , "Most irate and furious" , "Extremely mad" , "Most incensed kind of ingrates" , "Most characteristic of 1950s young men" .)