Medusa (9)
I believe the answer is:
jellyfish
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">medusa</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for jellyfish that I've seen before include "eg Medusa" , "Marine stinger" , "Gelatinous sea animal with tentacles" , "Sea animal with stinging tentacles" , "Sea creature with stinging tentacles" .)