- Star polygon (Wikipedia)
In geometry, a star polygon is a type of non-convex polygon. Regular star polygons have been studied in depth; while star polygons in general appear not to have been formally defined, certain notable ones can arise through truncation operations on regular simple or star polygons.
- Apostasy (Wikipedia)
Apostasy (/əˈpɒstəsi/; Greek: ἀποστασία apostasía, ‘a defection or revolt’) is the formal disaffiliation from, abandonment of, or renunciation of a religion by a person. It can also be defined within the broader context of embracing an opinion that is contrary to one’s previous religious beliefs. One who undertakes apostasy is known as an apostate. Undertaking apostasy is called apostatizing (or apostasizing – also spelled apostacizing). The term apostasy is used by sociologists to mean the renunciation and criticism of, or opposition to, a person’s former religion, in a technical sense, with no pejorative connotation.