Calculate; be of the opinion (6)
I believe the answer is:
reckon
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">calculate</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that calculate can be written as reckon)</span><br/ ><br/ >'<span class="explanation-format__original">be of the opinion</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for reckon that I've seen before include "Believe, suppose, judge" , "Estimate - judge" , "Have as opinion or count up" , "Suppose or calculate" , "Calculate or conclude" .)