a subdivision of a larger religious group
"The new sect broke away from the main church because they disagreed on baptismal practices."
An offshoot of a larger religion; a group sharing particular (often unorthodox) political and/or religious beliefs.
"The radical sect split from the main church because they believed traditional prayers were insufficient to save their souls."
In plain English: A sect is a small group of people who break away from a larger religion to follow their own strict rules and beliefs.
"The small religious sect held their service in an old barn far from town."
Usage: Use sect to describe small, often controversial groups that have split from a mainstream religion or ideology, rather than large, established faiths like "the Catholic Church." Avoid using it for any organized group with shared beliefs unless there is an implication of deviation or exclusivity.
The word "sect" comes from the Old French secte, which was borrowed from Late Latin secta. It originally meant a religious or philosophical group, possibly deriving from the Latin verb sequi meaning "to follow."