Directly related to "high" or "deep":
* altitude: The height of an object above sea level.
* altimeter: A device that measures altitude.
* altar: A raised platform, often in a church, used for religious ceremonies.
* alto: The second highest voice part in choral singing.
Figurative meanings:
* alternate: To switch back and forth between two things.
* alternative: A different choice or possibility.
* alter: To change something.
* alteration: A change or modification.
Less common words:
* altruistic: Unselfishly concerned for or devoted to the welfare of others.
* exalt: To praise or glorify.
* exalted: Raised to a high rank or status.
* subaltern: A subordinate officer or official.
These are just a few examples, and the root "alt" can be found in many other words. By understanding its meaning, you can better understand the meaning of these words and how they are used in the English language.