Horizon (noun)

1. The line at which the earth's surface and the sky appear to meet, especially as visible from a distance.
2. The limit of one's understanding, experience, or abilities.
3. The range of one's knowledge, interests, or prospects.
4. A future goal or aim.
5. The extent of something that is visible or known.

Origin:

From the greek word 'horizontas' meaning 'boundary, limit'.

Examples:

1. She watched the sun set over the horizon, painting the sky with oranges and pinks.
2. He has a broad horizon and is always looking for new experiences.
3. Her career horizon is limited by her lack of experience in the field.
4. Their horizon is set on building a sustainable future for their children.
5. His horizon of understanding was broadened by the knowledge he gained from his travels.