complement
US /ˈkɑːm.plə.ment/
UK /ˈkɑːm.plə.ment/

1.
a thing that completes or brings to perfection
:
•
The wine was a perfect complement to the meal.
•
Her skills complement his perfectly.
2.
the number or quantity of something, especially that needed to make a group complete
:
•
The ship has a full complement of crew.
•
We need a full complement of players for the team.