Casual, nonchalant (7)
I believe the answer is:
offhand
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">casual</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">nonchalant</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for offhand that I've seen before include "Where fingerprints are taken" , "Of speech, casual or curt" , "Casual or curt, like discarded glove?" , "Dismissive; curt" , "Discourteous" .)