Idealist, visionary (7)
I believe the answer is:
dreamer
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">idealist</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">visionary</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(dreamer is a kind of visionary)</span><br/ ><br/ ></span>
(Other definitions for dreamer that I've seen before include "He has visions" , "One imagines" , "description of an Oxford spire?" , "One who tends to live in an unreal world" , "One fantasising" .)