Savings (4,3)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">savings</span>' is the definition.<br/ ><span class="explanation-format__explanation">(nest egg can mean someone's savings)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for nest egg that I've seen before include "Fund put by as a reserve" , "Sum of money put by as a reserve" , "Money saved for the future" , "Fund for a rainy day" , "reserves" .)
(Another definition for nestegg that I've seen is " savings".)