This is the 7160th most frequent Russian word.
буэнос
The word "буэнос" is not a standard Russian word; it appears to be a transliteration of the Spanish word "buenos," meaning "good."
Буэнос is used here as a proper noun, possibly referencing a place.
Буэнос утром всегда светит солнце.
In Buenos, the sun always shines in the morning.
Буэнос is used here in the context of a greeting, phonetically borrowing from Spanish.
Как только он начал говорить своё «буэнос», я понял, что он из Аргентины.
As soon as he began saying his "buenos," I knew he was from Argentina.
Буэнос refers to a unique way of expressing the borrowed Spanish greeting.