nedeljni

недељни

/nědeːʎniː/

ADJECTIVE

Sunday

Nedeljni ručak kod mame je obavezan. — Sunday lunch at Mom's is a must.
weekly

Šef traži nedeljni izveštaj svakog petka. — The boss wants a weekly report every Friday.

In Serbia nedelja means both "Sunday" and "week", so nedeljni has both senses; sedmični unambiguously means "weekly".