Nonsectarian institutions are secular institutions or other organizations not affiliated with or restricted to a particular religious group.

What do you mean by non-sectarian?

: not having a sectarian character : not affiliated with or restricted to a particular religious group.

What does private non-sectarian school mean?

Non-sectarian schools are duly incorporated, owned and operated by private entities that are not affiliated to any religious organization while sectarian universities and colleges are usually non-stock, non-profit, duly incorporated, owned and operated by a religious organization.