Unworldly, green (5)
I believe the answer is:
naive
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">unworldly</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">green</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(green can mean naive or innocent)</span><br/ ><br/ ></span>
(Other definitions for naive that I've seen before include "Ingenous, easy to gull" , "Lacking judgment" , "Unsophisticated and gullible" , "Natural, unaffected" , "Unaffected or guileless" .)