Portion, instalment (7)
I believe the answer is:
tranche
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">portion</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that tranche is a type of portion)</span><br/ ><br/ >'<span class="explanation-format__original">instalment</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for tranche that I've seen before include "Portion of something, money perhaps" , "Share -- chanter (anag)" , "batch supplied" , "Instalment of e.g. loan" , "Part or block of something" .)