We say that it is 'setting,' but this is apparent motion, and not true motion. The same is true for the rising and setting of the moon and fixed stars.
There is another spectacular example of apparent motion that is different from true motion. Because the moon 'rises' in the east and 'sets' in the west, it is easy to think that it is "moving" from east to west. In fact, the moon's orbit around the earth is from west to east. The slow (monthly) orbit of the moon along with the 24-hour rotation of the earth give us the impression of the moon's apparent motion.
When the sun sets over the horizon, we say that the day is coming to a close or that night is falling.
Sunset. Evening/night time begins.
We say that it sets.
risen or set
Possibly you might say good morning.
horizon
you could say the horizon is a rizen' (as in the horizon is becoming higher)
Horizont
The land or ocean features would vary depending upon where you are, but one could safely say it rises over the eastern horizon.
its ορίζοντας (horizontas)
Depletion is when something goes down. For example: Let's say you had many people and a large amount of food. Over time that food will start to deplete (go down), until there is nothing left.
the sun rose