This is the 58th most frequent Latvian word.
vienu
"Vienu" in English means "one" (accusative case in Latvian).
In this sentence, "vienu" is used as an adjective indicating a singular item, meaning "one".
Es redzēju vienu interesantu grāmatu.
I saw an interesting book.
Here, "vienu" is used to define a specific quantity, emphasizing "one more."
Mēs palikām kopā vēl vienu stundu.
We stayed together for one more hour.
In this example, "vienu" is part of a negative construct "nevienu," meaning "none/no one."