Earthquake (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">earthquake</span>' is the definition.<br/ ><span class="explanation-format__explanation">(tremor is a kind of earthquake)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tremor that I've seen before include "A slight shake, perhaps of earth" , "Involuntary quiver" , "Bit of excitement" , "Vibration from earthquake" , "Quiver or vibration" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">earthquake</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Another definition for seism that I've seen is " Earth-shattering event".)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">earthquake</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>