This is the 5924th most frequent Russian word.
русским
"Русским" means "Russian" (in the dative or instrumental case or describing something related to Russians).
Here, 'русским' is used as an attributive adjective in the instrumental case, modifying 'народом' (people).
Я горжусь своим русским народом.
I am proud of my Russian people.
In this sentence, 'русским' is an attributive adjective in the instrumental case, modifying 'языком' (language).
Он занимается русским языком.
He is studying the Russian language.
Here, 'русским' is an attributive adjective in the dative case, modifying 'друзьям' (friends).