This is the 237th most frequent Russian word.
наши
"Our" or "ours."
In this sentence, 'наши' is a possessive pronoun in the plural form, meaning 'our', describing 'друзья' (friends).
Наши друзья решили прийти ко мне.
Our friends decided to visit me.
Here, 'наши' is again a possessive pronoun, modifying 'надежды' (hopes), in the plural form.
На детей возложены наши надежды.
Our hopes are placed on the children.
The word 'наши' refers to 'победы' (victories), indicating possession in the plural form.