Etymology From Medieval Latin sectarius + -an. Its corresponding etymology per the first sense is sect + -arian.
1
Of, relating to, or partial to a sect.
We were discussing solutions to the sectarian violence between Sunnis and Shias.
2
Dogmatic or partisan.
The Hariri-Aoun agreement has shown that Hezbollah can bring the national political system to a halt. This happened in the past several years, and it worsened conditions in sectors such as foreign debt, electricity output, rubbish collection, water delivery, and other essential services, to the discomfort of the majority of Lebanese who have spoken out intermittently against the oligarchy of sectarian leaders who rule the country.2016 October 22, Rami G Khouri, “Lebanese oligarchy preserves its interests once again”, in Al Jazeera, archived from the original on 13 May 2022:
Etymology From Medieval Latin sectarius + -an. Its corresponding etymology per the first sense is sect + -arian.
1
A member of a sect.
An American sectarian, who has always lived within the high walls and in the close atmosphere of our intense sect-life here, and has always been accustomed to the dragonism of sect-authority and sect-jealousy, —is utterly amazed when for the first time he looks over his native sect-walls and comes to see the freedom of thought and utterance within the old churches of Europe.1870, The Millennial Harbinger - Volume 41, page 423: