Boil (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">boil</span>' is the definition.<br/ ><span class="explanation-format__explanation">(simmering is a kind of boiling)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for simmer that I've seen before include "Bubble away" , "Cook in gently boiling water" , "Bubble on a low gas" , "Boil slowly at low temperature" , "Cook just below boiling point" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">boil</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for seethe that I've seen before include "Bubble, almost boil" , "exhibit anger" , "Bubble gently just below boiling point" , "Boil or become very angry" , "(Of liquid) boil" .)