Alpha (noun)

1. The first letter of the Greek alphabet (Α, α).
2. The highest rank or level, especially in a group or organization.
3. A man who is dominant or assertive in a group of men.
4. A dominant animal in a particular group or ecosystem.
5. An object, person, or group that serves as a model or example.

Origin:

From greek alphá, from phoenician ʾāleph, meaning "ox".

Examples:

1. The word "alphabet" comes from the first two letters of the Greek alphabet, alpha and beta.
2. He is the alpha and omega of this company and his decisions are always final.
3. The alpha male of the wolf pack leads the group and protects its members.
4. In this ecosystem, the alpha predator is the lion.
5. The team looked to their coach as their alpha and followed his example in all things.