Meaning of "go down" in Essential American English Dictionary

go down

phrasal verb with go us /ɡoʊ/ verb present participle going, past tense went, past participle gone

B1 to become lower in level:

Profits have gone down by about 2 percent.
Food prices have gone down recently.

B1 When the sun goes down, it moves down in the sky until it cannot be seen anymore:

I sat on the beach and watched the sun go down.

(Definition of “go down” from the Webster's Essential Mini Dictionary © Cambridge University Press)