This is the 2647th most frequent Japanese word.
本国
"Home country" or "homeland."
Here, 本国 ('home country') refers to the speaker's official country of origin or nationality.
彼は本国での生活を懐かしく思っています。
He misses the life in his home country.
In this sentence, 本国 ('home country') is used to describe the user's own country in terms of its economic status.
本国の経済は急速に発展しています。
The economy of the home country is rapidly developing.
This usage emphasizes 本国 ('home country') as the destination or the place one belongs to.