Frog or toad (9)
I believe the answer is:
amphibian
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">frog</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">toad</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ ></span>
(Other definitions for amphibian that I've seen before include "aircraft" , "One lives on land and in water" , "Animal able to live in both land and water" , "versatile vehicle" , "Vehicle for use on land or water" .)