Money saved for the future (4,3)
I believe the answer is:
nest egg
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">money saved for the future</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for nest egg that I've seen before include "Money laid aside for some future eventuality" , "Is it to encourage laying" , "Saved-up money" , "reserves" , "A saving for the future - by bird?" .)