Tier (noun)

1. A layer or a row of something.
2. A level or rank in a system, organization or society.
3. A group of related items, people or things.

Origin:

The word "tier" comes from the old french word "tiere" which means "layer" or "row". it has been used in english since the 14th century.

Examples:

1. The cake had three tiers.
2. The country is divided into three economic tiers.
3. He is in the top tier of professional athletes.
4. The company operates on a multi-tier system.
5. The store has different tiers of pricing for their products.