Informal, off-hand (6)
I believe the answer is:
casual
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">informal</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >'<span class="explanation-format__original">off-hand</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for casual that I've seen before include "Informal or blase" , "Informal or happening by chance" , "Informal or temporary" , "at ease" , "Occasional worker" .)