complementary

complementary /ˌkɑːmpləˈmɛntəri/ adjective
complementary
/ˌkɑːmpləˈmɛntəri/
adjective
Britannica Dictionary definition of COMPLEMENTARY
[more complementary; most complementary]
1 
: completing something else or making it better : serving as a complement
2 
— used of two things when each adds something to the other or helps to make the other better
3 
: going together well : working well together
4 
: not traditional : alternative