Octagon (noun)

1. A polygon with eight sides and eight angles.
2. A figure with eight straight sides and eight angles.

Origin:

Late 16th century, from latin octagonum, from greek oktagonon, from okto 'eight' + gonia 'angle'.

Examples:

1. The octagon shaped building was designed to be a place of worship.
2. The octagon table was perfect for eight people to sit comfortably around.
3. The octagon shaped sign indicated the location of a nearby tourist attraction.
4. The octagon shaped pool was surrounded by sun loungers.
5. The octagon shaped mirror added a touch of elegance to the room.