Windfall, godsend (7)
I believe the answer is:
bonanza
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">windfall</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(situation leading to an increase in wealth)</span><br/ ><br/ >'<span class="explanation-format__original">godsend</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that godsend can be written as bonanza)</span><br/ ><br/ ></span>
(Other definitions for bonanza that I've seen before include "Huge stroke of luck" , "Unexpected wealth or luck" , "Rich vein of gold or a sudden windfall" , "A sudden happening that brings good fortune" , "Lucky strike of wealth" .)